LIBRARY OF CONGRESS. 

il^jtOiB).^ W|n# :ftr 



UNITED STATES OF AMERICA. 



LAKES 



OP 



NOETH AMEEICA 

A BEADING LESSON 
FOR STUDENTS OF GEOGRAPHY AND GEOLOGY 



BY 



ISRAEL C. RUSSELL 

PKOFESSOR OF GEOLOGY, UXIVEESITY OF MICHIGAN 




Boston. U.S.A., Axn London 

PUBLISHED BY GIXN & COMPANY 

1895 



V 



A 



^ 



C/%CK- 



COPi-EIGHT, 1895, 

BY 

ISEAEL C. KUSSELL 



ALL BIGHTS BESEEVED 




Ann Arbor, Michigan, 
April 12, 1894. 



GROVE KARL GILBERT, 



>. GEOLOGICAL SmVEY, 
WASUiyOTOX, D. C. 



My Dear Sir: — 

It is now fourteen years since yon first guided my footsteps to the beaches of Lake Bonne- 
ville and poiuted out the striking contrasts in the sculpturing of the mountains above and below 
the horizon to which that ancient sea flooded the now desert valleys of Utah. For several years 
after the survey of Utah's former lake was completed, you directed my studies of the basins of 
similar lakes in Nevada, California, Oregon, and Washington; and through your advice and 
suggestions I was enabled to see many things that otherwise might have escaped notice. 

While writing this little book, which so inadequately describes some of the most interesting 
events in the later geological history of North America, I have made more use than I could well 
acknowledge of your volume on Lake Bonneville and of your more general discussion of the 
Topography of Lake Shores — books that are numbered among the classics of American geology. 

As a partial acknowledgment of this accumulated indebtedness, I beg to be allowed to 
dedicate this book to you. 

I remain, very respectfully, 



ISRAEL C. RUSSELL. 



PEEFATOEY I^OTE. 



A LARGE portion of the facts pertaining to the hxkes of North America, 
presented in this book, were gleaned by the writer during thirteen years' 
geological work for the National Government, and are recorded principal- 
ly in the publications of the U. S. Geological Survey. The facilities for 
exploration afforded by my connection with Government surveys enabled 
me to visit various parts of the United States, inclusive of Alaska, and to 
observe many phases in the topographical development of our continent. 

The publications of the U. S. Geological Survey, and of several State 
surveys, also contain the records of observations by others, relating to 
the subject here treated, which have been freely used. It is hoped that 
this popular presentation of a small part of the results of the various 
surveys referred to will serve to direct attention to the rich and varied 
store of information contained in the reports of my colleagues and fellow- 
workers. 

Besides the publications of official surveys, many papers relating to 
the subject here discussed have appeared in journals, proceedings of 
scientific societies, etc., to which references may be found in footnotes in 
this A''olume. 

The origin of lake basins and the history of the great cycles in the 

development of the relief of the land to which they pertain, have been 

discussed especially by Professor W. M. Davis, of Harvard University. 

Professor Davis has also read the manuscript of this Ijook and kindly 

given me the benefit of his criticisms and suggestions. 

I. C. K. 



i:nteoductiok 



Lakes liave their birth and death in the topographic development of 
the land. A certain class form a characteristic feature of lands recently 
elevated above the sea ; others belong with the earlier stages or 3'outh of 
streams ; while still others appear during maturity or in the old age 
of the rivers to which they owe their origin. Lakes of a different type 
are associated with modifications of topography due to glacial and to 
volcanic agencies, and to movements of elevation and depression in the 
earth's crust. 

Lakes, like mountains and rivers, have life histories which exhibit 
varying stages from youth through maturity to old age. The span of 
their existence varies as do the lives of animals and plants. In arid 
regions they are frequently born of a single shower and disappear as 
quickly when the skies are again bright ; their brief existence may be 
said to resemble the lives of the Ephemera. Again, the conditions are 
such that lakes perhaps hundreds of square miles in area, are formed each 
winter and evaporate to drj^ness during the succeeding summer ; these 
may be compared with the annual plants, so regular are their periods. 
Still others exist for a term of years and only disappear during seasons of 
exceptional aridity ; but the greater number of inland water bodies 
resemble the Sequoia, and endure for centuries with but little apparent 
change. So long are the lives of many individuals that human history 
has recorded only slight changes in their outlines, but to the geologist 
even these are seen to be of recent origin and the day of their extinction 
not remote. 

The tracing of the life histories of lakes and the recognition of the 
numerous agencies that vary their lives and lead to their death, gives to 
this l)ranch of physiography one of its ])rin('ipal cliarms. 



Viii INTEODUCTION. 

Lakes are also expressive of climatic conditions. In humid regions 
they usually overflow, are fresh, and vary but slightly in area or in depth, 
from season to season, and from century to century. In arid lands they 
are frequently without outlets and consequently alkaline and saline, and 
fluctuate in sympathy with even the minor changes in their climatic 
environment. 

The history of a lake begins with the origin of its basin and considers 
among other subjects the movements of its waters, the changes it pro- 
duces in the topography of its shores, its relations to climate, its 
geological functions, its connection with plant and animal life, etc. It is 
in this general order that the lakes of North America are considered in 
the present volume. The standpoint from which the subject is treated is 
tliat of the geologist and geographer, its relation to man being left to the 
archaeologist and the historian. 



OONTEI^TS. 



INTRODUCTION. 

Chapter I. 

ORIGIN OF LAKE BASINS. 

PAGE 

Depressions ox New Land Areas . ......... 1 

Basins due to Atmospheric Agencies ......... 3 

" " " Aqueous Agencies .......... .5 

" " " Glacial Agencies .......... 10 

" " " Volcanic Agencies .......... 17 

" " " Impact of Meteors .......... 24 

" " " Earthquakes 25 

" " " Organic Agencies 20 

" " " Movejients in the Earth's Crust ....... 28 

" " " Land-Slides ......... . . .31 

" " " Chemical Action 31 

Conclusion 32 

Chapter II. 

MOVEMENTS OF LAKE WATERS AND THE GEOLOGICAL FUNCTIONS 

OF LAKES. 

Tides 33 

"Waa'es and Currents 33 

Seiche ................ 35 

Temperature .............. 35 

Influence of Lakes on Climate ........... 37 

Influence of Lakes on the Flow of Streams ....... 38 

Lakes as Settling Basins ............ 39 

Mechanical Sediments ............ 41 



Chapter III. 
TOPOGRAPHY OF LAKE SHORES. 



Sea Cliffs 
Terraces 



43 
45 



X CONTENTS. 

PAGE 

EilBAXKMEXTS ............... 46 

Deltas 48 

IcE-BciLT Walls .............. 51 

Chapter IV. 

RELATION OF LAKES TO CLIMATIC CONDITIONS. 

Fresh Lakes. 

Chemical Composition ............ 55 

Types of Feesh Lakes . . . . . . . . . . . . . 57 

The Laueentian Lakes ............ 57 

The TJ. S. Lake SrsvET 57 

Chemistry of the "Waters of the St. La^-rexce ....... 59 

Eeosiox of Lake Shores ............ 60 

com3ieece and fisheries ............ 61 

Mountain Lakes. 

Lake Tahoe ......... ..... 63 

Lake Chelan ............. 65 

Saline Lakes. 

Saline Lakes of Oceanic Origin ... ..... 69 

Saline Lakes of Teeeestrial Oeigin ......... 70 

Chemical Precipitates ............ 71 

Great Salt Lake ............. 77 

Mono Lake ............... 83 

Chapter Y. 

THE LIFE HISTORIES OF LAKES. 

Lakes of Humid Regions ............ 90 

Lakes of Arid Eegions . ■ , . . . . . . . . . .93 

Chapter VI. 
STUDIES OF SPECIAL LACUSTRAL HISTORIES. 

Pleistocene Lakes of the Laurentian Basin ....... 96 

Lake Agassiz ........ ...... 103 

Pleistocene Lakes of the Great Basin 106 

Lakes of the Eejiote Past ............ 114 

Index 122 



ILLUSTRATIOXS. 



Paoe 

Plate 1. Ox-bow Lakes, Lower Mississippi ....... 8 "^ 

'• 2. View of Stocktox Bar, Utah . . . . . . . . .10 

'• 3. Map of Stocktox Bar, L'tah ........ 12 

'■ 4. Map of Gravel Bar retainixg Hl'jiholdt Lake, Xevada . . .14 

" 5. Map of Crater Lake, Oregon ........ 20 

•' G. Sketch of Abert Lake, Oregon ........ 26 

•' 7. Chart of Lalrextiax Lakes, showing Prevailing Cfrrents . . 34 / 

" 8. Sea-cliff in Boulder Clay, South Manitou Island, Lake 

Michigan ............ 42 

9. Sea-cliff in Sandstone, Au Train Island, Lake Superior . . .44 

10. Embankment formed in Lake Bonneville, AVellsville, Utah . 46, 

11. Gravel Spit, Shore of Au Train Island, Lake Superior . . 48 ■ 

12. A Recurved Spit, Grand Traverse Bay, Michigan . . . . 50 i, 

13. Sea-cliffs and Terraces formed on the Shore of Lake Bonneville, 
Oquirrh Range, Utah . . . . . . . . • . 52 ■ 

14. IMap of Saline and Alkaline Lakes in the Arid Ricgion . . . 70 -- 

15. Map of Great Salt Lake, Utah, showing Changes in Area . . 7S 

16. The High Sierra, from Xorth Shore of Mono Lake, California . 84 / 

17. Map of Mono Lake, California 88 / 

18. Map of Lake Iroquois . . . . . . . . . .08 

19. Map of Lakes Bonneville and Lahontan ...... 10!i ' 

20. Tufa Towers on the Shore of Pyramid Lake, Nevada . . . 110 

21. Tcfa Crags, showing Successive Deposits, Carson Desert, Xevada 112 

22. Typical Specimen of Thinolitic Tufa . . . . . . . ]16 

23. Pyramid Island, Pyramid Lake, Xevada ...... 120 - 

Figure 1. Cross Sections of the Canons of Canadian and ^Ii>i;a IIivers, 

Xew Mexico ........... 18 

2. Profile of a Sea-cliff and Terrace ....... 44 

3. Profile of a Cut-and-Built Terrace ...... 45 

4. Sketch Map of an Embankment ........ 47 

5. Map of Sand Bar about the Head of Lake Supkimor . . 48 

6. Map of Sand Bar on the South Shoue of Lake Ontahio . . 40 

7. Section of a Delta .......... 50 

8. Diagram showing the Rise and Fall of Lake Lahontan . . 108 

9. Diagram showing the Relation of the Terraces of Lake Lahontan 
to Pyramid Lake Ill 



LAKES OF NORTH AMERICA. 



CHAPTER I. 

ORIGIN OF LAKE BASINS.^ 

Difficulties arise in classifjdng lake basins, similar in cliaracter to 
those met witli when a systematic discussion of glaciers, rivers, mountains 
and other features of the earth's surface is attempted. That is, there are 
no natural groups separated by hard and fast lines, into Avhich they 
naturally fall. Certain types may be selected, however, answering to 
genera among plants and animals, about which most lakes may be 
grouped. In selecting these types we are guided by their mode of origin, 
and are thus led to an incomplete genetic classification, based on the 
natural agencies which produce depressions in the earth's surface. 

Depressions on ncAv land area. — On lands recently elevated above 
the sea or left exposed by the evaporation or drainage of inland water bodies, 
there are usually inequalities, and water frequently collects in the depres- 
sions and forms lakes. There are comparatively few lakes of this type in 
North America, for the reason that large portions of our coasts are sinking 
and new land areas are rare. The lakes of Florida, liowever, are good 
examples of this class. They are surrounded by marine rocks of recent 
origin, and are but slightly elevated above the sea. In fact, all of the 
topographic features of Florida indicate immaturity. The luxuriant 
vegetation of the southeastern coastal plain, masks the slight inequalities 
of the surface, and, b}' clogging the slack drainage, leads to a greatei- 

1 This subject has been discussed by numerous writers, and has led to controversies not 
yet ended. The most extended and most systematic treatment that it has received may 
be found in an essay by W. M. Davis "On the classitication of lake basins," in Boston 
8oc. Nat. Hist., Proc, vol. 21, 1882, pp. .315-381. The numerous references given in this 
paper constitute the best bibliography of the subject available. xVn important supplementary 
paper by the same author is republished as an appendix of the present volume. 



2 LAKES OF NORTH AMERICA. 

expansion of the lakes than would appear if the land was barren. The 
wealth of vegetation tends also to preserve the original barriers from 
erosion. About the southern shore of Hudson bay there is another area 
recently abandoned by the sea, on which there are lakes, but this region 
is so little known that it cannot be pointed to with confidence as a case 
in point. In the Great Basin, as the vast area of interior drainage 
between the Sierra Nevada and Rocky mountains is termed, there are 
many lakes, some of them of large size, which occupy depressions in the 
surfaces of sedimentary deposits left exposed by the. evaporation of much 
larger Pleistocene water bodies. Great Salt lake and Sevier lake, Utah, 
occupy the lowest depressions in valleys formerly flooded by the waters 
of a great inland sea to which the name Lake Bonneville has been 
applied. Pyramid, Walker and other lakes in Nevada, occur in vallej^s 
which are deeply filled with the sediment of anotlier ancient water body 
named Lake Lahontan. In these instances, however, and in many others 
of similar character throughout the Arid Region, the positions of the 
present lakes on the approximately level floors of desert valleys have 
been partially determined by recent movements of large blocks of the 
earth's crust adjacent to lines of fracture, and by the unequal deposition 
of alluvial material swept out from mountain valleys and deposited on the 
adjacent plain. These recent changes have modified the character of the 
basins now occupied by lakes, but essentially they are depressions on new 
land areas, and form the most typical examples of their class that can 
be found in this country. 

There are new land areas about the borders of the Laurentian lakes, 
which have been left exposed by the recession of still greater lakes that 
occupied the same basin at a comparatively recent date, and also in the 
region drained by Red river in Minnesota and Canada, formerly flooded a 
vast lake named in honor of Louis Agassiz. Along some of our rivers, 
also, which flow through ancient valleys now deeply filled, there are 
narrow areas of new land, similar to the recently exposed borders of the, 
Laurentian lakes. In all of these instances, however, the lakes formed 
in the inequalities of the surface are small and of little importance. 

Lakes on new land areas are surrounded by topographic forms 
expressive of youth, and are themselves evidence of topographic im- 
maturity. When drainage is established on such areas the basins are 
soon emptied. The lives of lakes of this class, as is the case with all 
terrestrial water bodies, depend largely on climatic conditions. They 
may continue longer in one region than in another, but in the 



OEIGIN OF LAKE BASINS. 3 

ordinary course of topographical development are transient features. 
In humid regions they are drained more quickly than where the rainfall 
is small. They are fresh or saline according as they overflow or are 
without outlet. 

On old land areas where the streams have reached maturity or old 
age, the inequalities of the surface due to the accidents of original depo- 
sition are removed, and lakes of the class here considered are absent. 
This is shown in a striking manner by contrasting Florida Avith the 
adjacent Appalachian region. In the former, lakes are abundant, and 
their surroundings give abundant evidence of recent origin ; in the latter, 
the topographic forms as well as the terranes from which they have been 
carved, bear the stamp of antiquity. 

Lands that have been subjected to intense glaciation, or have re- 
ceived a covering of glacial deposit, are essentially new land area, and 
bear evidence of topographic youth ; but the lakes characteristic of such 
rejuvenated lands Avill be considered in advance in connection with other 
results of glacial action. 

Basins due to atmospheric ag-encies. — The weathering of rock 
surfaces progresses unevenly, on account of varying hardness and the 
varying degree to which they yield to chemical changes. This is 
noticeable particularly on granitic areas, as granite is especially prone to 
disintegration, and produces uneven surfaces when weathered. The 
tendency to decay unequally, as weathering progresses, probably exists 
in all rocks ; and it is to be expected that hills and hollows would result 
for the action of the atmosphere on any variety of deposit, especially if 
marked variations occur in its texture and composition. This tendency is 
most easily detected when the bedding is nearly horizontal, and large 
sheets of nearly level strata are exposed to the sky. 

The products of weathering are removed by water in solntion and in 
suspension, and are blown away by the wind. When removed by water, 
the formation of basins is checked by the cutting of outlets. When 
carried away by the wind, depressions known as " wind-erosion basins " 
are left.^ These are basins of excavation or true rock basins, and in this 
respect resemble depressions eroded l)y glaciers. Some observers have 
concluded that many of the rock basins commonly ascribed to glacial 

1 Numerous examples of shallow, saucer-sliaped depressious in shale, due to the action 
of the wind on areas bare of vegetation, in the southeastern part of Colorado, have recently 
been described by G. K. Gilbert. Jour, of Geol., vol. 3, 1895, pp. 47-49. 



4 LAKES OF NOETH AMERICA. 

action, are wind erosion basins or areas of pronounced rock decay, from 
which glaciers have removed the loosened material without deeply abraid- 
ing the unweathered rock beneath. The mode of origin of rock-basins 
is still a matter of controversy, but it seems evident to the writer, not 
only from reading the various views advanced by others, but also from 
personal observation in many lake regions, that rock basins have been 
formed by each of the agencies mentioned as well as by a combination of 
the two. The formation of basins by ice erosion and by chemical solution 
might be included among the results of atmospheric action, but under 
the classification here adopted they fall in different categories. 

Atmospheric agencies also lead to the formation of basins by depo- 
sition ; as for example, when sand is drifted into dunes. Drifting sand 
frequently travels across the country for scores of miles in the direction 
of the prevailing winds, and sometimes obstructs valleys so as to cause 
lakes to form. The best illustration of this occurrence known to the 
writer, is in the central part of the State of Washington. The drainage 
of one of the deep narrow valleys known locally as " Coulees," which 
trench the Great Plain of the Columbia, has been obstructed by immense 
sand dunes, so as to form a dam and retain the water of Moses lake.^ 
Below the dam of drifted sand there are several springs fed by lake 
waters percolating through the obstruction. These serve to keep the 
waters of the lake fresh. The springs below the sand drifts unite to form 
Alkali creek, which in winter sometimes has sufficient volume to reach 
the Columbia, but in summer suffers from evaporation, and terminates 
in a series of alkaline pools. 

Drifting sand may lead to the destruction of a lake as is illustrated 
by an example in western Nevada. The branch of Truckee river, 
supplying Winnemucca lake, is partially obstructed by wind-blown sand, 
and a struggle for supremacy between the river and the encroaching 
dunes is in progress. Should the sands prevail and a dam be formed, 
the water supply of Winnemucca lake would be diverted to Pyramid 
lake, and its basin would soon become desiccated. 

Volcanic dust is carried great distances by air currents, and might 
accumulate in a valley so as to obstruct its drainage. No lakes, retained 
by dams of this nature, are knowji on this continent, although thousands 
of square miles in the western part of the United States were covered, in 
Pleistocene and recent times, to a depth of many feet with fine volcanic 

1 I. C. Russell, "Geological Reconnoissance in Central Washington," U. S. Geol. Surv. 
Bulletin, No. 108. 



OEIGIN OF LAKE BASINS. 5 

deposits, which in some instances have assisted other agencies in pro- 
ducing ineqnahties of the surface. 

Basins due to aqueous ag-encies. — In this class of basins there are 
two important subdivisions : «, basins due to the action of streams, and 
i, basins due to the action of waves and currents. In each subdivision, 
but more especially in the first, there are basins formed by excavation 
and basins due to deposition, or basins due to destructive and to construc- 
tive agencies. Frequently the two processes have united in the formation 
of a single depression. 

a. Basins formed hy streams. — The drainage of new land areas, es- 
pecially in humid regions, soon obliterates the depression due to the 
original inequalities of the surface, as already explained ; but other basins 
resulting from the action of the streams themselves are formed. 

When the topography of a young land area is yet immature, and more 
especially when the elevation is considerable and the climate humid, the 
even flow of the draining streams is a^^t to be interrupted by rapids and 
Avater-falls, at the bases of which excavation is accelerated and depressions 
formed. The deepening of such portions of stream-beds, results princi- 
pally from the friction on their bottoms and sides, produced by sand and 
stones moved by the swift currents. Some distance below falls and 
rapids, the current usually slackens, and the waters deposit a portion 
of their load. A basin of this character is now being excavated below 
Niagara falls, and other examples ma}^ be seen in the channels of many 
mountain streams. Even on old land areas like the southern portion of 
the Appalachian region, where the streams are engaged in cutting down 
synclinal table-lands in Avhich hard and soft strata alternate, small basins 
of the character here referred to are of common occurrence. Should a 
stream channel in which such inequalities have been produced be aban- 
doned as a line of drainage, the basins would be transformed into lakes. 

The best example of a lake basin of considerable size formed at tlie 
base of a water-fall, that has come under the writer's notice, is in the 
Grand Coulee, near Coulee City, in the State of Washington. Tlie 
Columbia river now skirts the northern and western borders of the vast 
lava-covered region known as the Great Plain of the Columbia, or more 
familiarly as the "Big Rend country/" but in Pleistocene times its present 
course Avas obstructed l)y glaciers which descended from the mountains 
to the north, and it was forced to cut across the Big Bend through a 
series of deep canons in the lava. Its temporary course was through 



6 LAKES OF NORTH AMEEICA. 

Grand Coulee, and near the present site of Coulee City, it plunged over 
a precipice about two hundred feet liigli, and formed a cataract of the 
nature of Shoshone falls, Idaho, but rivaling Niagara in grandeur. Two 
basins were excavated in the rocks at the base of the falls, which were 
left as lakes when the glaciers retreated and the Columbia returned to its 
old channel. These lakes still exist although desert slnaibs grow on the 
brink of the precipice over which the waters of the flooded and ice-laden 
river previously thundered. Each of the lakes is by estimate a mile 
long and half a mile broad, and of considerable depth, as is shown by the 
dark blue color of their waters when seen from the crest of the encircling 
cliffs.i 

The deeper positions of stream channels excavated during floods, may 
be transformed into lakes when the waters subside or when the course of 
a stream is changed. This is shown by the temporarj^ ponds remaining 
in many humid countries during droughts when water no longer flows 
through the customary surface channels, but is more common in arid 
regions where the streams are subjected to still greater fluctuations. 

The basins just described are formed principally by excavation, those 
noted below are due to deposition. 

In regions of rapid erosion, a high grade and consequently rapid 
tributary, may bring to a sluggish trunk stream more detritus than it is 
able to carry away. When this happens, the main stream is more or less 
completely obstructed, and lakes may result. Basins of this nature occur 
in the steep-walled valleys of the Sierra Nevada and Rocky mountains, 
and are to be expected wherever streams have cut back their trenches far 
into an upland and receive high-grade tributaries. 

The alluvial cones about the bases of mountains in the Arid Region 
are frequently several miles in radius, and have a thickness near the 
mouths of the gorges from which the material forming them was dis- 
charged, of two or three thousand feet or more. When such deposits are 
formed on the opposite side of a valley only a few miles across, they may 
unite one with another so as to form transverse ridges and give origin ta 
basins. Alluvial cones are especially conspicuous in regions where the 
drainage in the valleys is weak or entirely wanting, thus favoring the 
formation of basins in the manner just described. Lake Tulare, in 
southern California, may be cited as an example, as it is retained on a. 
broad alluvial plain by material swept out by torrents from canons in the 

1 I. C. Eussell, "Geological Reconnoissance in Central Washington," U. S. Geol. Surv. 
Bulletin, No. 108. 



ORIGIN OF LAIiE BASINS. 7 

Sierra Nevada. In regions where the conditions are most favorable 
for the growth and preservation of allnvial cones, there is but little 
rain-fall, and the material deposited in the valleys is apt to be porous 
and of such a character that it absorbs water readily; for this reason 
lakes may be absent and the land remain desert-like and arid although, 
basins exist. 

A lack of close adjustment in the transporting power of streams may 
sometimes be observed even in humid countries, and in regions of mild 
relief. As described by G. K. Warren,! the excess of material brought 
by Chippew^ay river to the Mississippi, obstructs the main stream so as 
to cause an expansion of its waters known as Lake Pepin. An approxi- 
mation to the same conditions occurs where Wisconsin river and Illinois 
river join the " Father of Waters"; but in these instances it is only in 
the low water stages that the ponding becomes conspicuous. A tendency 
in the same direction was noted by J. W. Powell while making his ad- 
venturous journey through the caiion of the Colorado ; dangerous rapids 
were encountered at localities where lateral streams had swept debris into 
the main channel. 

Perhaps the best examples of lakes held by obstructions deposited 
by lateral streams that can be cited, occur in valleys draining to the 
Assiniboine, ]Manitoba. The lakes referred to, are situated in valleys that 
were cut down to a gentle slope when the abundant drainage of glacial 
lakes flowed through them ; but the weaker modern streams are unable 
to maintain such a faint grade, and are being silted up where tributaries 
enter. Long narrow lakes are thus formed above delta-fans built by 
streams having a higher grade than the main valley.^ 

The separation of lakes Brienz and Thun, Switzerland, has been cited 
by Davis as an example of the partitioning of a valley by the union of 
deltas from opposite sides. Interlaken stands on the beautiful alluvial 
plain thus formed. Several other similar examples in centiul Europe 
have been described by various authors. 

Lakes retained by the deposits of lateral streams and by alluvial 
cones, pertain to young and immature streams, and are incident to their 
work of erosion. As topographic development progresses, these water 
■bodies are obliterated, but when streams reach maturity and old age, lakes 
of another class appear along their courses. 

1 Am. .lour. Sci., vol. 10, .3d ser., 1878, p. 420. 

2 Warren Upham, " Report on Lake Agassiz," Canadian Geol. and Nat. Ili.st. Surv., Ann. 
Rep., vol. 4, 1888-89, p. 22 B. 



8 LAKES OF NORTH AMEEICA. 

In the case of mature streams that have cut down the seaward portion 
of their valleys nearly to base-level, that is approximately to the level of the 
ocean, and where rivers rising in mountainous regions flow across low 
plains, it frequently happens that the more energetic tributaries towards 
their head waters bring in more detritus than the gently flowing trunk 
streams are able to carry, and deposition takes place on their bottoms and 
over their flood plains. When the main stream is flooded and inundates 
its valley, its load is deposited most abundantly on the immediate borders 
of its channel, and builds up lateral embankments or levees. When this 
happens, the lateral tributaries joining the main stream in its lower course, 
may not be able to fill up their valleys as rapidly as the borders of the 
main river are raised, and are consequently ponded. Many shallow lakes 
have been formed in this manner along the borders of the large rivers 
flowing to the Gulf of Mexico. The most conspicuous examples occur 
along the banks of Ked river, Louisiana, where lateral lakes, as has been 
pointed out by Davis, are arranged along the side of its levees like the 
leaves on a twig. 

In the maturity and old age of rivers, when they meander in broad 
curves through a wide flood plain, as in the case of the lower Mississippi, 
the loops are frequently cut off, as shown on Plate 1, and crescent-shaped 
or " ox-bow " lakes are left. Examples of lakes of this character on a 
small scale may be seen along the border of many sluggish brooks which 
traverse deeply filled valleys. 

In the formation of low-grade deltas, like those now in process of con- 
struction at the mouths of the Mississippi, Nile, Ganges, etc., the waters 
break through the levees of the main stream during floods, and form 
branching channels or " distributaries," which in their turn bifurcate in a 
similar manner, and build up their channels and inundated borders. In 
such instances low areas are frequently surrounded by embankments, and 
left as basins containing shallow lakes. Many examples of this occur- 
rence are found on the broad delta of the Mississippi. Of these Lake 
Pontchartrain is the largest at the present time. Lake Borgne, in the 
same region, is another example, not yet con;pleted. The delta lands of 
the Rhine, in Holland, and of other rivers in northern Germany, contain 
many lakes and swamps of the type here considered. The celebrated- 
Zuyder Zee was formed in part as a delta basin and in part by the con- 
struction of natural embankments adjacent to a low shore. Miniature 
illustrations of this method of forming basins may be seen on the deltas 
of many small streams, built in lakes and ponds. 



Lakes of North America. 




OX-BOW LAKES, LOWER MISSISSIPPI 



ORIGIN OF LAKE BASINS. 9 

The overloaded streams from glaciers also form levees, in much the 
same manner as in the case of more mature streams. These embank- 
ments are apt to be formed of both coarse and fine material, and sometimes 
enclose low areas, so as to obstruct their di-ainage and give origin to lakes 
and j)onds. Young streams, on account of the amount of debris con- 
tributed to them, thus in some instances, simulate to a certain degree 
the behavior of more mature rivers. Small lakes of the class here referred 
to occur about the southern border of the Malaspina glacier, Alaska. 

h. Basins formed hy waves and currents. — Basins are frequentl_y 
formed along the ocean's shore and on the border of lakes, where sand 
and gravel bars have been built across the entrances of bays, or extend 
from headland to headland so as to cut off a curve of the shore. Numer- 
ous examples of water bodies that have been isolated in this wa}^ occur 
along the Atlantic coast and about the shore of the Laurentian lakes. 
The history of some of these secondary lakes may be easily read from 
the exceedingly valuable series of charts published by the U. S. Coast 
and Geodetic Survey and by the U. S. Lake Survey. It frequently hap- 
pens that lakes separated from the ocean by narrow sand bars, are fresh. 
This is due to the fact that the movement of water through the shore 
deposits is from the land seaward, and the originally saline waters in such 
enclosures have been flooded out. The seaward flow of underground 
water also explains Avhy fresh water may be obtained in wells on sand 
bars of the character here referred to. 

Besides living examples of the class of lakes here considered, there 
are basins of a similar origin still to be seen about the borders of lakes 
that have ceased to exist. In the Great Basin, and especially on the 
borders of the valleys formerly flooded by the waters of lakes Bonneville 
and Lahontan, there are small lakes and enclosed basins not now flooded, 
which are due to the formation of embankments about the margin of 
those ancient water bodies. The vallej^s formerly covered with the 
water of these great seas to the depth of man}- hundreds of feet are now 
for the most part parched and arid, and desert shrubs cover the em- 
bankments of sand and gravel on which the surf formerly broke. Only 
a few of the secondary basins formed along those ancient shores can be 
referred to at this time. 

At the town of Stockton, Utah, about fifteen miles south of Great Salt 
lake, there is an immense gravel bar, formed near the highest stage of 
Lake Bonneville, which sweeps completely across the entrance of a valley 
and retains the waters draining from the southward, so as to form Rush 



10 LAKES OF NORTH AMERICA. 

lake. This lake is variable in area and depth. Sometimes it measures 
two and one-half miles in breadth and is about five feet deep ; again, 
during seasons of unusual drought, it evaporates to dryness. The bar 
to which it owes its origin rises one hundred and fifty feet above its 
surface, and under more favorable climatic conditions would retain a lake 
many square miles in area. The view of the great bar at Stockton and 
the map of the same locality, presented on Plates 1 and 2, are so graphic 
and truthful that time need not be taken to describe them. 

Another example of a lake basin formed by a bar crossing the entrance 
of a lateral valley, is furnished by Lake Annie, near Fort Bidwell, Cali- 
fornia. The ancient lake on the border of which the bar now retaining 
Lake Annie was constructed, flooded Surprise valley, in the northeast 
corner of California, during Pleistocene times, but is now represented 
by exceedingly shallow alkaline lakes. Lake Annie is a few hundred 
3"ards in diameter, and is kept fresh and sweet by the escape of its surplus 
waters through the embankment retaining it. 

Perhaps the best of all the examples of the class of water bodies now 
under consideration, that can be referred to, is Humboldt lake, Nevada. 
This lake occupies a secondary basin in one of the valleys formerly flooded 
by the waters of Lake Lahontan. When the ancient lake was lowered so 
as to approach extinction, a bar was formed directly across the end of Hum- 
boldt valley, where it opens out onto the Carsen desert. The waters of 
Humboldt river were retained by this bar when Lake Lahontan fell so 
as to leave it dry, and a lake formed above it. The waters escaped across 
the bar and cut a channel, so as to partially drain the basin above ; but in 
recent years an artificial drain has been constructed in the opening, and 
the lake now covers a greater area than it would had the natural con- 
ditions remained unmodified. A map of the bar retaining Humboldt 
lake, on which much of the history of its origin can be read, is shown in 
Plate 4.1 

Basins due to g-laoial agencies. — On the surfaces of glaciers, espe- 
cially on the loAver portions of neve regions, there are frequently shallow 
depressions holding lakes which give variety and an additional charm to 
the wintry landscapes with which they are surrounded. Xo case is known 
in which these lakes are perennial, although they form in the same locali- 
ties year after year. They are of little geological interest, for the reason 

1 I. C. Eussell, "Quaternary History of Lake Lahontan," U. S. Geol. Surv., Monograph 
No. 11. 






I I 







ORIGIN OF LAKE BASINS. 11 

that they leave but slight if any permanent records. Their waters are 
so clear that practically no sediments accumulate in them. On conti- 
nental glaciers, however, such lakes might exist from year to year, and 
perhaps receive sufficient deposits to leave recognizable records after the 
ice disappeared. Certain deposits of exceedingly fine, light colored, clay- 
like material termed loess^ in the upper jNIississippi valle}^ are believed 
by some persons who have studied them, to have been accumulated 
in lakes on the surface of the great ice sheet which formerly covered 
that region. 

When glaciers flow through valleys surrounded by mountains, they 
sometimes obstruct the drainage of lateral valleys so as to cause lakes to 
form. The dams in these instances are formed by the ice in the main 
valleys. The type of this class of lakes is furnished by Marjelen lake, 
Switzerland. In this instance a lateral valley below the snow line is 
dammed by Aletsch glacier which flows past its mouth. The lake is 
variable in area, being sometimes a mile long and at other times completely 
drained owing to the enlargement of the tunnel beneath the ice dam 
through which it discharges. 

In Alaska there are many lakes of the Marjelen type. About the 
southern bases of the foot-hills of Mt. St. Elias there are several water- 
bodies that are held in check by the Malaspina glacier. The largest of 
these, known as Lake Castani, at the southern end of the Chaix hills, is 
two or three miles long and a mile broad when at its highest stage, and 
discharges through a tunnel eight or nine miles long, beneath the ice 
sheet to the south. The position of this sub-glacial river. can be traced 
by a depression in the surface of the ice, and when above it, the muffled 
roar of the imprisoned flood can be heard far below one's feet. Of many 
lakes similar to Lake Castani in the same general region, perhaps the most 
instructive is one discovered by John Muir, in Stikine valley, British 
Columbia, near the Alaskan boundary. In this instance a lake about 
three miles long and approximately a mile broad, and receiving the drain- 
age of five or six residual glaciers, is held in a lateral valley by Toyatte 
or Dirt glacier, which floAvs past its entrance. The outlet of the lake is 
tlirough a tunnel in the ice, which is sometimes enlarged so as suddenly to 
empty the basin and cause a flood in Stikine river. 

Tlie lakes formed when glaciers obstruct the drainage, are varialjle 
in size, owing to changes in their draining tunnels, and are frequently 
emptied, as in instances just cited. The surfaces of these lakes are many 
times covered with floatino- ice, which is left stranded when their waters 



12 LAKES OF XOETH AMERICA. 

escape. They are unusually turbid with silt brought to them by glacial 
streams, and leave important deposits to mark their sites when the condi- 
tions are no longer favorable to their existence. 

The most widely knoAvn- example of the formation of terraces about 
the borders of a glacial-dammed lake, is furnished by the Parallel Roads 
of Glen Roy, on the west coast of Scotland. The origin of these terraces 
was a fruitful source of controversy for many years ; but the explanation 
that they are due to the action of the waves and currents of a lake held in 
a lateral valley by a glacier flowing past its entrance, has finally been 
accepted as satisfactory. 

It is Avorthy of note, that lakes of the type just described, not 
only occur in mountain valleys, but also about the ends of mountain spurs 
projecting into encircling ice sheets, as on the northern border of the 
Malaspina glacier. The deltas and terraces formed in such lakes may 
remain in unexpected places, as high up on the side of a mountain, whei? 
the retaining glacier is melted. 

When the land bordering an ice sheet slopes towards the ice, the 
escape of the waters formed by the melting of the glacier, as well as 
streams from the adjacent areas, is checked, and marginal lakes, some- 
times of large size, are formed. Two small examples of this class of 
water-bodies were seen by the writer at the northern base of the Chaix 
hills, Alaska. During the close of the Glacial epoch, when the ice-sheet 
occupying northeastern North America was retreating, there came a time 
when the southern margin of the ice faced a northward-sloping land- 
surface, and lakes far larger than the present Laurentian lakes, were 
formed. The largest of these ancient seas, named Lake Agassiz, covered 
the region in ^Minnesota and Canada now drained by Red river, and 
others were formed in the Laurentian basin. 

When glaciers melt, the rock surfaces left exposed are frequently 
planed, grooved and polished. In such instances, the evidences of the 
friction of the flowing ice and of the sand and pebbles frozen into it, are 
pronounced and unmistakable. These marks of abrasion are frequently 
buried and concealed by deposits of debris of various kinds which were 
transported on the surface of the living glacier or enclosed in its mass, 
and left as superficial deposits when the ice melted. In the lower por- 
tions of mountain valleys previously occupied by ice streams, and over the 
outer border of regions formerly covered by continental ice sheets, the 
deposits of debris are in many instances so abundant that the worn rock 
surfaces beneath are completely concealed. 



Lakes of North A?rKi?icA. 



'' '^if^Mf'^VT T ^'^-'^ ' ' f l'< r')' T\r^ 




RUSH AND TOOELE VALLEYS. UTAH. 

showing the 

WAVE BUILT BARRIER. 

Bj H. A. "Wheeler. 



70 ■/to. CoiUo*trt 




Vertical Section from jc to Kush Lake 
VerUdtU. Settle, double th^ /fonxonOit' 



STOCKTON BAR UTAH. (AFTER GILBERT.) 
Compare -vvitli Plate 2. 



ORIGIN OF LAKE BASINS. 13 

The study both of living glaciers and of the records left by ancient 
glaciers has proven that flowing ice both erodes and deposits, and that 
basins result from each of these processes. 

Whether a glacier shall erode its beds or deposit material upon it, 
seems to depend largely on its grade, and consequently on its rate of 
flow. In high-grade valleys among mountains formerly occupied by 
glaciers, the higher and steeper portions of the main avenues of ice 
drainage, are usually intensely glaciated, and the worn and rounded 
surfaces are frequently bare of glacial deposits ; but the lower portions of 
such valleys, especially where they open out on a plain, are almost always 
heavily covered Avith morainal material. Not only are moraines deposited 
in the mouth of the valleys, but sheets of gravel, clay, and boulders are 
spread over the bottom of the glaciated troughs, showing that the ice- 
streams in such situations deposited material on the surface over which 
they flowed. 

Above the region of most intense glaciation in lofty mountains there is 
a zone, embracing the higher summits, where polished and scratched 
surfaces are rare, and where there is but little debris. This upper 
region was the site of the neves or snow fields of the glaciers that abraded 
the rocks at a lower horizon and deposited their loads when the grade 
decreased and the ice currents were slackened. A similar association of 
a region of glacial abrasion and an outer zone of glacial deposition, may 
be recognized in countries formerly covered by continental ice sheets. In 
the region of most intense glaciation, in • the case of both Alpine and 
continental glaciers, as has been shown by extended observation, there 
are numerous rock basins, the sides and bottoms of which are polished and 
striated. A large number of lakes of this character in the Cordilleran 
region have been examined by the writer, and their study left no doubt 
that they were due to glacial action. These rock basins are confined to 
areas of intense glaciation, and are absent from adjacent areas where 
the conditions are essentially the same, except that glaciers have not 
passed over them. 

It is impossible to point to examples where living glaciers are actually 
engaged in wearing out rock basins, since their work of abrasion is neces- 
sarily concealed ; neither is it possible to satisfactorily observe the process 
by which gla( iers polish and striate rock surfaces, yet no student of the 
subject doubts that these results are produced by moving ice charged with 
sand and gravel. The nature of the evidence leading to the conclusion 
that many rock basins are due to glacial abrasion, is of the same character 



14 LAKES OF NORTH AMERICA. 

as the evidence from which it is concluded that many smoothed and stri- 
ated rock surfaces are due to the same agenc}". The rock basins of the 
character here referred to, are confined to regions of former glaciation, not 
only in America but on other continents, and are wanting where other 
evidences of ice action are absent. The interiors of the basins themselves 
are smoothed and striated, and bear incontestable evidence that in part at 
least, they are due to the abrasion of sand-charged ice. These more 
general considerations are in such harmony with what is known of the 
work of ice streams, that the}^ carry even more weight than special 
studies of individual lakes. 

Although the evidence leading to the conclusion that many rock 
basins in glaciated regions are essentially of glacial origin, seems to the 
writer to be conclusive, it is but just to state that, even after thirty years 
of ardent controversy, there is still a difference in opinion among geolo- 
gists and others, in reference to the abrading power of moving ice, and its 
ability to erode rock basins. The literature bearing on this question is so 
voluminous that it is impracticable to present even an abstract of it at the 
present time.^ 

Without considering further the results of the destructive action of 
glaciers, let us see what is the character of the basin they produce by 
construction. Fortunately in this connection there is little difference of 
opinion. 

The terminal moraines left by Alpine glaciers in their retreat, fre- 
quently form crescent-shaped piles of debris, convex down stream, which 
act as dams, and retain lakes. Hundreds and probably thousands of 
examples of lakes held in check by obstructions of this character, exist in 
the valleys of the Cordilleras, and are common in every formerly glaciated 
mountainous region. The Twin lakes in the Arkansas valley, Colorado,^ 
several small lakes on the west side of ]Mono valley, California,^ and 
numerous sheets of clear water in the "Wasatch mountains, Utah, so well 
known to tourists, are types of this class. Similar lakes occur about the 

1 This subject has received special attention since tlie appearance of a celebrated paper 
by Ramsay, "On the glacial origin of certain Swiss lakes," Quar. Jour. Geol. Soc, vol. 18, 
p. 185; but a unanimous conclusion has not been reached, as may be seen by consulting 
Nature for 1893-94. The present status of this interesting controversy is presented in a 
paper by T. G. Bonney, and accompanying discussions, in the Geographical Journal of the 
Royal Geographical Society, vol. 1, 1893, pp. 481-504. 

2 F. V. Hayden, U. S. Geol. and Geog. Surv. of the Territories. Ann. Rep., 1874. pp. 
47-53. J. J. Stevenson, Explorations and Surveys vrest of the 100th Meridian (" Wheeler 
Survey " ), vol. 3, 1875, pp. 441-444. 

3 I. C. Russell, U. S. Geol. Surv., 8th Ann. Rep.. 1886-87, PL 35. 



OEIGIN OF LAKE BASINS. 15 

extremities of the existing glaciers of this country, from the High Sierra, 
California, northward to Alaska. These are retained by moraines, from 
which the ice has receded within a few years, thus leaving not even the 
shadow of a doubt as to their mode of origin. 

Many of the lakes of Scandinavia and of Switzerland are retained by 
ancient moraines, as are also in part, the long, deep lakes on the Italian 
side of the Alps, and draining to the Po. The most striking example of 
the type of lake here described, however, which has been studied by the 
writer, is Lake Wakatipu, on the east side of the Southern Alps, New 
Zealand. This magnificent water body, surrounded on all sides by lofty 
snow-clad peaks, has many of the characteristic features of lakes Como 
and Maggiore, and is not second to them in majesty and beauty. 

The di'ainage of mountain vallej^s, in which moraine-dammed lakes 
have been formed, is frequently so abundant that stream channels are cut 
through the obstructions, and the lakes drained. When this occurs, 
beautiful grass-covered vales or " parks," as they are called in the Rocky 
mountains, are formed. These charming valleys are quite as beautiful 
and frequently furnish as great a contrast to the ruggedness of the sur- 
rounding scenery, as did the gem-like lakes that preceded them. 

In most instances the deep mountain valleys of North America, 
now occupied by moraine-dammed lakes, were excavated by streams 
previous to being glaciated, and only served temporarily as avenues for 
ice drainage. Their main topographic features are due to stream erosion 
and weathering. Only minor changes such as the smoothing and round- 
ing of their bottom contours, can be ascribed to glacial abrasion. 

The general sheets of debris left after the retreat of continental glaciers 
and by the melting of the expanded extremities of large Alpine glaciers, 
are usually uneven on account of the manner of their deposition, and 
abounds in depressions which may hold water. In many instances the 
lakes originating in this manner are without surface outlets, their sur- 
plus water escaping by percolation. 

On the formerly ice-covered portion of northeastern North America, 
the lakes occupying depressions in the general covering of superficial 
material are so numerous that the position of the southern boundary of 
the old ice sheet may be approximately traced on a drainage map of the 
region by noting the southern limit of the lake-strewn portion. The old 
land surface south of the glacial boundary, is almost entirely free from 
undrained basins ; and in this, as well as in other respects, presents a 
striking contrast to the rejuvenated surface of the land to the north. 



16 LAKES OF NORTH AMERICA. 

The lakes occupying depressions on the glacial drift number hundreds of 
thousands. They vary in size from mere tarns up to splendid water- 
sheets many square miles in area. In portions of Minnesota, Michigan, 
and adjacent areas, where the drift is unusually deep, the lakes in irregu- 
lar depressions on its surface sometimes number a score or more to the 
square mile. It is estimated that in Minnesota alone, there are not less 
than ten thousand lakes of this class, besides many swamps and marshes 
marking the sites of former lakes of the same type, which have become 
choked with vegetation. 

Numerous lakes of the same character as those on the drift of the North- 
eastern States and Canada, occur about the southern margin of Malaspina 
glacier, Alaska, in depressions in moraines left by the retreat of the ice 
within the past few years. These very modern basins, some of which are 
still occupied in part by the ice of the retreating glaciers, are similar in every 
way to the basins on the moraine-covered surfaces just referred to, and are 
surrounded by topography of the same character, thus leaving no room for 
doubting that each of the two series is due to similar agencies. 

When the general sheet of debris left after the retreat of continental 
glaciers does not completely mask the pre-glacial topography, former 
valleys are sometimes dammed, and lakes of another type produced. In 
many instances these lakes are long and narrow, and indicate, to some 
extent, by their form, the character of the ancient drainage lines they 
occupy. Again, they may be broad water-bodies, and occupy ancient 
drainage basins, the outlets of which have been closed. Pre-glacial 
valleys may be deepened by ice erosions, as well as obstructed, and the 
two processes may unite to form lakes, as is believed to have been the 
case in the group of " Finger lakes " in the central part of New York state. ^ 

Still another type of lake basins, due to glacial agencies, is found in 
unconsolidated water-laid material deposited about the borders of ice- 
sheets. When the stream-borne debris from a glacier is abundant it 
forms low alluvial cones and sand and gravel plains, which may surround 
or cover isolated ice masses. When such buried ice masses finally melt 
a depression is left, and may be water-filled. The borders of such lakes 
are of loose material which slides into the depression and forms steep 
banks. The inclination of the enclosing walls depends upon the nature 
of the material of which they are composed. Broad tracts of sand and 

1 A. P. Brigham, "The Finger lakes of New York," Geographical Soc. Am., Bull., vol. 
25, 1893. K. S. Tarr, "Lake Cayuga a rock basin," Geological Soc. Am., Bull., vol. 5, 1894, 
pp. 339-356. 



ORIGIN OF LAKE BASINS. 17 

gravel with hollows of the character just described, scattered over their 
surfaces, are known as ''pitted plains," and find their most acceptable 
explanation in tlie hypothesis just suggested. 

Lakes Walden and Cochituate, Massachusetts, are believed to be 
examples of the class of lakes here referred to, and to owe their origin to 
the melting of ice masses tliat were eitlier partially or wliolly buried in 
gravel and sand.^ Lakes of similar character in southern JNlichigan, 
where glacial deposits are unusually abundant, might also be cited in this 
connection. These lakes occupy crater-shaped depressions in the surfaces 
of gravel and sand plains, of the character that would be expected to 
result from the burial and subsequent melting of ice masses, in the 
manner outlined above. 

From tliis brief account of the action of ice in obstructing drainage, 
it will appear that lake basins are formed not only on account of the 
damming of streams by the glaciers themselves, but by glacial erosion 
and glacial deposition ; and in still other ways, in connection with the 
deposits made by streams. 

Basins due to volcanic ag^encies. — Inequalities on the surfaces of 
lava sheets sometimes give rise to lakes in much the same manner as 
lakes are formed on the surface of glaciers. Examples of such basins in 
various stages of extinction, by di'ainage and sedimentation, occur on 
portions of the lava plains of Washington and Idaho. 

A lava stream may cross a valley so as to obstruct its drainage and 
cause a lake to form above it, in much the same way as glaciers dam 
lateral valleys. A large lake was formed in this manner, probabl}^ in 
Pleistocene times, on the Yukon river, Alaska, where it is joined by Pelly 
river. A series of lava flows there filled the river valley from side to side 
to a depth of several hundred feet, and formed a dam which retained 
the waters of the Yukon, and gave origin to a broad Avater-body known 
as Lake Yukon.'^ The obstruction has since been cut through along the 
southern margin of the old channel, leaving a series of basaltic precipices 
on the right bank of the river. 

1 "Warren Upliam, Boston Soc. Nat. Hist., Proc, vol. 25, pp. 228-242. 

2 W. M. Dawson, "Report on an exploration in the Yukon district," Canadian Geol. 
Nat, Hist. Surv., Ann. Kep., 1887-88, p. 132 B. 

I. C. Russell, "Notes on the surface geology of Alaska," Geol. Soc. Am., Bull. vol. 1, 
1890, pp. 140-148. 

C. W. Hayes, "An expedition through the Yukon district," National Geog. Mag., 
vol. 4, 1892, p. loO. 



18 LAKES OF NORTH AlVIEEICA, 

Another instance of the formation of a lake on account of the filling- 
•of a valley by a lava flow, but on a much smaller scale than the example 
cited above, has been observed by the writer, at the junction of Canadian 
and Mora rivers, New Mexico. Canadian river, for a distance of perhaps 
a hundred miles, flows through a steep-walled gorge, in which for a space 
of several miles, near where Mora river joins it, there is an inner gorge, 
as indicated in the following cross section : 




Fig. 1. — Ceoss Section- of the CaSons of Cai^adian a^t) Moea Eiyees, New Mexico 

(J. J. Stetexson). 

The valleys excavated by Canadian and Mora rivers were filled to a 
depth of 400 feet by basalt, as indicated by vertical hues in the section, 
and were subsequently eroded to a depth of 230 feet deeper than before 
the obstruction. The lake which existed above the lava flow has been 
drained, and only indefinite traces of its former presence now remain.^ 

Similar instances of the damming of streams by lava flows, are known 
on the west slope of the Sierra Nevada, but are also of ancient date. 
The lakes that were formed have been drained, and their bottoms trans- 
formed into grassy valleys. 

Two small lakes, held in check by a recent lava stream, now exist at 
the Cinder cone, near Lassens peak, in northern California. Beneath the 
lava retaining these lakes there is a sheet of fine lacustral marl and dia- 
tomaceous earth, showing that a former lake was partially filled by the 
molten rock, now hardened into compact basalt.^ 

Another class of lakes due to volcanic agencies, occupy the bowls of 
extinct craters. These occur in various situations, being sometimes at 
the summits of high volcanic cones, and again in depressions in broad, 
featureless plains. The walls enclosing them are sometimes formed of 
compact lava, but more frequently consist of scoria, lapilli, and so-called 
ashes, blown out of volcanic vents during periods of violent eruption. 

1 This instructive locality has been described by J. J. Stevenson, in Am. Phil. Soc, Proc, 
1880, pp. 84-87. 

2 J. S. Diller. " A Late Volcanic Eruption in Northern California." U. S. Geol. Surv., 
Bulletin Xo. 79, 1891. 



ORIGIN OF LAKE BASINS. 19 

At Ice Spring buttes, a group of small volcanic craters, near Fillmore, 
Utah, there is a pool of water in the throat of an extinct volcano, Avhich 
occupies a depression formed by the recession of the lava that once rose in 
and partially filled the crater.^ 

The Soda ponds on the Carson desert, near Ragtowu, Nevada, occupy 
lapilli craters, the rims of which rise 20 to 80 feet above the surface of 
the adjacent plain. The larger pond has an area of 268 acres and a 
depth of 147 feet, and its surface is 60 feet below the general level of 
the desert.^ 

A crater similar in character to those holding the Soda ponds, occurs 
on one of the islands in INIono lake, California, and is occupied by alkaline 
waters. The water within the crater stands at the same level as the sur- 
face of the surrounding lake, a connection between the two being main- 
tained by percolation through the intervening embankment of incoherent 



One of the numerous craters near San Francisco peak, Arizona, is said 
to hold a lake at a considerable altitude above the adjacent country. In 
the summit of Mt. Toulca, Mexico, a deep depression produced by violent 
eruptions is stated by Davis to have been similarly transformed. 

In many volcanic regions in other countries, lakes of this class are 
known to occur. They are common in Italy, on North Island, New 
Zealand, and are reported to occur in the Caucasus, on the Solomon 
Islands, in India, etc. A typical example of a water-filled crater is fur- 
nished by Laacher See, on the border of the Eifel, Germany, and has been 
described and illustrated by Edward Hull."^ 

Still another class of lakes due to volcanic agencies occur where the 
summits of volcanoes have been blown away by the energy of the con- 
fined vapors within ; or when the base of a volcanic pile has been melted 
so as to cause it to subside into the conduit from which the material com- 
posing the mountain was extruded. 

It is believed that basins have resulted from each of these processes, 
but observations on their actual formation are lacking. It is known, 
however, that volcanic mountains of large size are sometimes literally 
blown awa}^, as happened in the case of Krakatoa, in 1886. 

1 G. K. Gilbert. " Lake Bonneville." U. S. Geol. 8urv., Monograph Xo. 1. 1800, p. :^>22. 

2 I. C. Kussell. "Lake Laliontan." U. S. Geol. Surv., Monograph Xo. 11, 1885, pp. 
72-80. 

3 I. C. Kussell. "Quarternary History of Mono Valley, California." I'. S. Geol. Surv., 
8th Ann. Kep., 1880-87, p. 873. 

* " Volcanoes : Past and Present." Contemporary Science Series, pp. 122-123. 



20 LAKES OF NORTH AMERICA. 

In several volcanic regions there are deep, circular depressions, known 
as " calderas " or " crater-rings," which are believed to have been formed 
by the blowing away of the mountains that once existed above them. A 
somewhat complete series can be established between craters that have 
been partially broken down by subsequent eruptions, and crater-rings, 
about which there are in some instances no vestiges of the original craters 
remaining. There is evidence also in the character of the rocks surround- 
ing crater rings, and in the adjacent topography, which sustains the 
hypothesis of their violent origin. 

Two of the largest calderas yet discovered, occur in Italy, and are 
occupied by Lago di Bracciano and Lago di Bolsena. As described 
by J. W. Judd, the first-named is nearly circular, with a diameter of 
six-and-a-half miles ; the second, somewhat less regular, has a length 
from north to south of ten-and-a-quarter miles, and a breadth of 
nine miles. The only examples of crater-rings in North America 
that can be referred to are Gustavila lake, Mexico, of which the 
writer has been unable to obtain detailed information, and Crater lake^ 
Oregon. 

Crater lake has been described by C. E. Dutton,^ and is considered by 
him as worthy of a high rank among the wonders of the world. It is 
situated in the Cascade mountains, in northwestern Oregon, thirty miles 
north of Klamath lake, at an elevation of 6239 feet above the sea. It is 
nearly circular, without bays or promontories, as indicated on the accom- 
panying map, Plate 5, and is from five to six miles in diameter. The 
cliffs of dark basaltic rock encircling it, rise precipitously to heights vary- 
ing from 900 to 2200 feet, and nowhere offer an easy means of access to 
the basin within. They plunge at once into deep water, without leaving 
even a platform at the water's edge wide enough for one to walk on. 
There are no streams tributary to the lake, and no visible outlet. The 
waters probably escape by percolation, as the precipitation of the region 
is in excess of evaporation, and if an escape were not furnished the basin 
would be filled to overflowing-. 

Near the southwest margin of the lake, about half-a-mile from shore, 
a cinder cone, named Wizard island, rises from the Avater to a height of 
645 feet. This cone is regular in form and has a depression in its sum- 
mit, thus showing at a glance that it is of volcanic origin, and is in fact 
a miniature crater of eruption. From the base of Wizard island two 

1 Science, vol. 7, 1886, pp. 179-182. Also, 8tli Ann. Rep., U. S. Geol. Surv., 1886-87, 
pp. 157-158. 



Lakes of Xokth Amkeica. 
1 22° 15 ' 10' 




42501 



I22'l3'' 



4250- 



CRATER LAKE, OREGON. (AFTER U. S. GEOLOGICAL Survey.) 

Contour-interval 200 feet ; soundings in feet ; lake surface OJJO feet above sea level. 



ORIGIN OF LAKE BASINS. 21 

streams of hardened lava extend outward towards the great walls enclosing 
the lake, but do not reach them. 

The sounding line has shown that Crater lake has a maximum depth 
of 2000 feet and is the deepest lake now known in North America ; its 
nearest rival being Lake Tahoe. The full depth of the basin measured 
from the crest of the enclosing cliffs, is from 2900 to 4200 feet. 

The rugged slopes encircling the lake as well as the island that seem- 
ingly floats on its placid surface, are forest covered, thus softening and 
rendering picturesque the otherwise oppressive grandeur of the scene. 

More remarkable, however, than the unique scenic features of Crater 
lake, is the story of its origin. The site of the great depression was once 
occupied by a volcanic mountain which reached far above the highest 
point on the cliffs now enclosing it, and was probably as conspicuous a 
member of the sisterhood of mountains of which it formed a part, as any 
of the neighboring peaks, but the once prominent pile has been removed 
so as to leave the profound gulf that now fascinates and startles the 
observer. The character of the sculpturing on the outer slope of the 
truncated mountain shows that it was eroded, both by streams and by 
glaciers, before the catastrophe that carried away its summit and left only 
a hollow stump to mark the site of the ice-crowned peak that formerly 
gleamed in the sky. 

The removal of the summit of the mountain is supposed to have been 
due to a mighty explosion, similar to that which blew off 5000 feet from 
Krakatoa ; or else that the mountain was melted from Avithin and its 
summit engulfed so as to leave the depression now partially filled with 
placid waters. Of these two hypotheses, the second seems to accord best 
with the observed facts, for the reason that fragmental deposits on the 
surface of the adjacent country, of the character that would be expected 
had the summit of the mountain been blown away, have not been recog- 
nized. Subsequent to the removal of the summit of the mountain, 
renewed volcanic energy of a mild character built the crater-island within 
the crater-ring. 

A circular depression in Init little disturbed stratified rocks which 
bears some resemblance to a crater-ring, and which seems likely to furnisli 
the key to the origin of the calderas of Italy and other regions, has 
recently Ijeen discovered in Arizona, about 25 miles southeast of the 
town of Flagstaff. This unique basin has been carefully studied by 
G. K. Gilbert, but no account of it from his pen has come under the 
writer's notice. The observations stated below are niainlv from a 



22 LAKES OF NORTH AMERICA. 

description of a model of the locality published in the American 
Geologist.^ 

This " crater " in what is known as Coon butte, is three-fourths of a 
mile in diameter and its bottom is depressed from 500 to 600 feet below 
the encircling rim, which rises 150 to 200 feet above the surrounding 
plains. The surface limestone of the region, elsewhere horizontal, is 
steeply inclined quaquaversally in the cliffs around the crater ; and 
masses of the same stratum and of an underlying sandstone, are strewn 
in irregular profusion outward from the crater to the base of the butte, 
which has a diameter of about two miles. In less amount, the same 
debris reaches outward on all sides over a nearly circular area to a 
distance of about four miles. No lava, bombs, lapilli, or other vol- 
canic products, were seen. The formation of this irregular crater-like 
depression is referred by Gilbert, perhaps provisionally, to a steam 
explosion. 

The occurrence in the vicinity of Coon butte of hundreds of frag- 
ments of meteoric iron, up to about a pound in weight, and of several 
pieces weighing from 20 to 600 pounds, led at first to the thought 
that possibly a meteorite of great size might have struck this spot, buried 
itself out of sight and thrown up a crater-like rim. This hypothesis, 
upon being tested, was abandoned, however, because the volume of the 
raised rim and of the rock fragments scattered about, was found to corre- 
spond very closely with that of the depression beloAV the level of the 
plain : and for the second reason, that a magnetic survey failed to 
indicate the existence of any large mass of meteoric iron competent to 
make such a crater, Avithin at least a depth of many miles. This second 
objection, however, is now considered of but little weight, since the 
meteoric fragments found about the crater, although now magnetic, 
have undergone alterations of a character which seem to indicate that 
when they first reached the earth they might not have had any or but 
slight magnetic properties. The changes produced in the surface frag- 
ments are due to atmospheric influences, which •would not reach a deeply 
buried body. 

The crater-like depression in the summit of Coon butte is without 
water, for the reason that it is situated in an arid region, but under 
humid skies would no doubt be transformed into a lake. 

The only counterpart of Coon butte as yet discovered, is situated in 
the central part of the Peninsula of India, some 200 miles northeast of 

1 Vol. 18, 1894, p. 115. 



ORIGIN OF LAKE BASINS. 23 

Bombay. This remarkable crateriform lake, known as Lonas lake, is 
described by R. D. Oldham ^ as follows : 

" The surrounding country for hundreds of miles consists entirely of 
Deccan trap, and in this rock there is a nearlj^ circular hollow, about 300 
to 400 feet deep and rather more than a mile in diameter, containing at the 
bottom a shallow lake of salt water without any outlet, whose Avaters 
deposit crystals of sesquicarbonate of soda. The sides of the hollow to 
the north and northeast are absolutely level with the surrounding 
country, while in all other directions there is a raised rim, never exceed- 
ing 100 feet in height and frequently only 40 or 50, composed of blocks 
of basalt, irregularl}- piled, and precisely similar to the rock exposed on 
the sides of the hollow. The dip of the surrounding traps is always 
from the hollow, but very lov>". 

"It is difficult to ascribe this hollow to any other cause than volcanic 
explosion, as no such excavation could be produced by any known form 
of aqueous denudation, and the raised rim of loose blocks around the edge 
appears to preclude the idea of a simple depression. It is true that there 
is no sign of any eruption having accompanied the formation of the crater ; 
no dyke can be traced in the surrounding rocks ; no lava or scoriae of later 
age than the Deccan trap period can be found in the neighborhood. The 
raised rim is very small, and cannot contain a thousandth part of the rock 
ejected from the crater, but it is impossible to say how much was reduced 
to fine powder and scattered to a distance, or removed by denudation. 

" Assuming that this extraordinary hollow is due to A'olcanic explosions, 
the date of its origin still remains to be determined. That this is long 
posterior to the epoch of the Deccan traps is manifest, for the hollow 
appears to have been made in the present surface of the countr}'-, carved 
out by ages of denudation from the old lava flow. To all appearance 
the Lonas lake crater is of comparatively recent origin, and if so it 
suggests that, in one isolated spot in India, a singularl}- violent explosive 
action must have taken place, unaccompanied by the eruption of melted 
rock. Nothing similar is known to occur elsewhere in the Indian 
Peninsula." 

Besides the obstructions to drainage produced l)y overflows cf lava, 
and by volcanic explosions, it may also be noted that volcanic dust and 
ashes, ejected from volcanoes during times of violent eruptions, may be 
deposited over the adjacent countr}^ in such a manner as to choke the 
streams and possil)ly form dams which A\-()uld retain lakes. This process 
1 " A Manual of the Geology of India." 2d cd. Calcutta, 1890. pp. 10. 20. 



24 LAKES OF NORTH AMERICA. 

has already been referred to in connection with the formation of basins 
through the action of eolian agencies. 

Lava streams frequently cool on the surface while the liquid rock below 
is still flowing. In such instances, when the crust is sufficiently strong 
to sustain itself, the molten lava beneath flows out, leaving caverns. 
Openings of this nature may become water-filled and form subterranean 
lakes, or their roofs may fall in, leaving depressions open to the sky. 
Lakes and ponds occupying such depressions are thought to exist on the 
vast lava sheets of Oregon, Washington and Idaho, but clear, simple 
examples of the type are not at hand. 

On a small lava flow on an island in Mono lake, California, there are 
depressions occupied in part by water, which are due to a general sub- 
sidence of the surface on account of the outflow of molten rock below and 
the crumpling of the crust into concentric, crescent-shaped ridges. 

Another mode in which volcanic agencies may produce depressions is 
by subsidence of the surface about volcanoes, due to the removal of lava 
from subterranean reservoirs, but no instances where this has certainly 
occurred have yet been observed in this country. 

Basins due to the impact of meteors. — The study of the origin of 
the crater-like forms on the surface of the moon recently made by Gilbert,^ 
was suggested by the hypothesis that depressions on the earth's surface 
might result from the impact of meteoric bodies. This suggestion has 
already been referred to in describing Coon butte, and is one of great 
interest. Up to the present time, however, no basins on the earth's sur- 
face are known which can be ascribed to this agency. 

If the earth was formed by the coming together of a large number of 
previously independent meteoric bodies, as is thought to have been the 
case by Lockyer, all evidence of such an occurrence in the relief of its 
surface is wanting. Small meteors are known to reach the earth every 
day, and a number have been discovered weighing many tons, but such 
an event as the earth coming in contact with a planetary mass a mile or 
several miles in diameter, as seems to have happened in the case of the 
moon, is not only unrecorded in history, but, as just stated, there is no 
evidence in the surface features of the earth to show that such an 
event has happened in recent geological time. If the earth once had 
a pitted surface, like the moon, and was scarred by vast crater-like 

1 " The Moon's Face," Philosophical Society of Washington, Bull. vol. 12, 1893, pp. 
241-292. 



ORIGIN OF LAKE BASINS. 25 

depressions, each one the record of the piercing of its surface and the 
burial within its crust of a planetary mass previously revolving independ- 
ently in space, the date of the last of the catastrophes which produced 
that condition must have been so remote that erosion has removed all 
surface evidence of the fact. Still farther negative evidence may be cited, 
inasmuch as no buried meteoric masses recognized as such, have been 
found in the rocks now forming the earth's surface. This is not j^i'oof, 
however, that the meteoric hypothesis, as applied to the earth, is not true, 
as the main events in that drama are assumed to have been enacted before 
the formation of the stratified rocks now recogfnizable. 

Basins due to earthquakes. — During earthquakes there are undula- 
tions of the surface of the regions affected which sometimes produce per- 
manent elevations and depressions and thus affect the drainage. The 
passage of earthquake Avaves through loose deposits may cause them to 
become more compact and perhaps produce depressions on their surfaces. 
In these and probably other ways, basins may be formed by earthquakes 
and give origin to lakes. 

The best examples of lake basins in America, resulting directly from 
earthquake shocks, occur in what is known as the " Sunk country " in 
southeastern Missouri and northeastern Arkansas. A series of severe 
disturbances, known as the New Madrid earthquake, affected that region 
between 1811 and 1813, and caused both elevations and depressions in 
the forest-covered flood plain of the Mississippi. This region has recently 
been examined by W J McGee,i who reports that a low dome some 20 miles 
in diameter, was upheaved athwart the course of the JNIississippi and that 
the river was held in check for a brief period, but soon cut a channel 
through the obstruction. An adjacent area some one huncbed square 
miles in area, was depressed and is still, in part, occupied by lakes in which 
the trunks of trees killed by the inundation are standing. 

During earthquakes in regions occupied by unconsolidated rocks, 
water is sometimes forced to the surface with great violence, probably on 
account of the compression of porous, water-charged strata, and rises 
fountain-like above the surface. The water brings with it quantities 
of sand and mud which are deposited around the points of discharge and 
serve to enlarge the depressions produced by the violent outrush. When 
the fountains cease to play these small crater-like basins remain as ponds. 

1 "A Fossil Earthquake," in Geo!. Soc. Am., Bull., vol. 4, pp. 411-415. 



26 LAKES OF NORTH AMERICA. 

Basins clue to org-anic ag-encies. — The study of coral reefs lias 
shown that bodies of sea water are sometimes cut off from the ocean, 
although rarely completely sej^arated, by the growth of reefs of 
living coral adjacent to coasts, or as atolls about isolated islands and 
" banks." Lakes of this nature perhaps occur at the south end of Florida, 
and on the West India islands, but no well defined instances have been 
described. 

The formation of peat in temperate latitudes affords another illustra- 
tion of the manner in which organic agencies lead to the formation of 
lakes. The growth of the moss known as Sphagnum, from which peat is 
largely formed, may obstruct sluggish drainage ; and its unequal growth 
in swampy areas leads to the formation of mounds with depressions in 
their summits. The best known illustration of this type is Drummond 
lake, in Virginia, but many smaller examples occur in other swampy 
areas. It has been suggested that the basins in peat swamps may have 
originated by the burning of the bogs during times of excessive drouth. 
That this might happen is evident, but no authentic case of such an 
occurrence is known to the writer. 

On the vast tundras skirting the Arctic ocean in both the Old and 
the New World, there are vast numbers of ponds and lakes held in 
depressions in the frozen bogs, and surrounded by banks of moss and 
other vegetation. These water-bodies have probably originated in various 
ways, but in some instances their birth may be traced to the luxuriant 
growth of vegetation in spring and early summer about the borders of 
lingering snow banks. When the vegetation of the tundras awakens 
after its long winter sleep, its growth is surprisingly rapid, and the snow 
drifts that last longest are surrounded with luxuriant mosses and brilliant 
flowers. When such accumulations of snow finally melt, the vegetation 
on the areas they occupied is less in amount than on the surrounding- 
surfaces. The tundra increases in depth by the partial decay and 
freezing of the lower portion of the vegetation forming its surface, arid 
the greatest thickness of frozen soil occurs where the vegetation is most 
luxuriant. For these reasons, the places where snow banks form year 
after year, become depressed in reference to the general surface, and give 
origin to lakes. 

In sub- Arctic regions, as on the Aleutian islands, mosses and 
herbaceous vegetation grow luxuriantly, and among the hills sometimes 
ojDstructs the drainage by reason of the formation of a deep peaty soil by 
its partial decay. 



^ o 



'-■1.1 : 1 ]Ui(i:jn Mi 

' : \ ; > \\'; ),V \i' I ; ! m 




ORIGIN OF LAKE BASINS. 27 

Beaver dams afford still another illustration of the manner in which 
drainage is obstructed and lakes formed by organic agencies. Beavers 
formerly lived over nearly the whole of North America, and are still 
found in limited numbers in the Northern states and Canada, and extend- 
ino- southward alouQ- the Cordilleras at least as far as New Mexico. The 
dams they constructed with great intelligence and skill, across small 
streams, retained drift logs and floating leaves, thus leading to the 
accumulation of deposits which obstructed the drainage for a long time 
after they had been abandoned by the animals that built them. The 
ponds and swamps due to the work of beavers number tens of thousands, 
and have produced important changes in the minor features of the surface 
of the continent. ]\Iany of these ponds, after becoming 'choked with 
vegetation and converted into peat swamps, have been drained and 
furnish rich garden-lands. 

Where brooks and creeks flow through forested regions, it fre- 
quently happens that large trees fall across them and retain the sticks 
and leaves swept along by the current. When such a start is made, the 
mud carried, especially during freshets, is lodged among the leaves and 
branches, and tends still farther to obstruct the drainage and lead to the 
formation of swamps and lakes. This process has been observed espe- 
cially in Red river, Louisiana, where timber rafts several square miles in 
area, and covered with living vegetation, form floating islands and dam 
the streams so as to cause their waters to spread out in shallow lakes 
twenty to thirty miles in length.^ 

Numerous instances in the Yukon river, in Alaska, were observed by 
the writer, where lateral branches of the stream and the passage ways 
between islands, were closed by accumulations of drift logs that greatly 
obstructed the flow of the waters. In some instances these accumulations, 
called " wood yards " by steamboa,t men, are several acres in extent. 

Still another way in which organic agencies lead to the formation of 
basins may be observed in swamps where vegetable matter buried beneath 
mud and clay is undergoing decomposition. Openings similar to those 
produced in alluvial deposits by the violent escape of water during earth- 
quakes, but not necessarily connected with such disturbances, are formed 
in marshes by the violent escape of gases from below. Instances of this 
occurrence have come under the writer's notice on Smoke Creek desert, 

1 Charles Lyell. " Principles of Geology." 11th ed., Vol. 1, p. 441. Humphreys & Abbott. 
"Heport on the Physics and Hydraulics of the Mississippi," Professional Papers, Corps of 
Engineers, U. 8. A., 1861, p. ;J7. 



28 LAKES OF NOETH AMEEICA. 

Nevada, and on swampy areas near Sandusky, Ohio. When these gas 
eruptions occur, the soft mud is sometimes thrown to a distance of one or 
two hundred feet, and conical depressions are formed which in some of the 
instances observed, are twenty feet or more in depth. The caving in of 
"the banks' holes sometimes leads to the formation of pools fifty or sixty 
feet in diameter. The circular ponds frequently to be seen in swampy 
regions, when not due to encroaching vegetation, probably, in many 
instances, originated in the manner here noted. 

The generation of gases, principally carbureted hydrogen, in the soft 
mud of the Mississippi delta, causes elevations known as " mud lumps," 
which in some instances are twenty-five feet high. Inequalities pro- 
duced in this manner might easily lead to the obstruction of drainage 
and the formation of lakes, but no instance of such an occurrence seems 
to have been reported. 

It has frequently been observed that cattle on visiting swampy places 
carry away considerable quantities of mud, adhering to their feet and 
matted in their hair. In arid countries where drinking places are usually 
small and widely scattered, they are visited by cattle and other animals in 
large numbers and a marked enlargement of the water holes is produced 
in the manner just stated. This process was more important when 
the plains of North America were densely inhabited by bisons. Many 
perennial pools and still more numerous depressions that are water-filled 
only during rainy seasons, are known as "buffalo-wallows," and are 
believed to owe their origin to a great extent to the carrying away of 
mud entangled in the thick hair of the animals after which they are 
named. 

In the Appalachians there are several water holes, usually on the 
crests of ridges, that are called "bear-wallows," and are said to have 
been formed by bears that sought moist places in which to cool them- 
selves during hot weather. As is Avell known, swine have a similar 
habit. 

Basins due to movements in the earth's crust. — Great changes in 
the earth's crust have produced continents and ocean-basins, while smaller 
movements on land areas have resulted in the formation of mountains and 
valleys. During the growth of mountains it sometimes happens that the 
region between different systems or between two or more ranges, becomes 
enclosed so as to form a basin. This process has been in action in various 
localities since land first appeared, and during the course of geological eras 



ORIGIN OF LAKE BASINS. 29 

must have resulted in the formation of many hikes ; but examples of water 
bodies of this type are rare at the present time, principally for the reason 
that the deformation of the earth's crust usually goes on slowl}- and the 
depressions formed are drained or filled with sediments as rapidly as 
they are formed. 

The best examples on this continent of basins formed by the upheaval 
of mountains around them, occur in the great area of interior drainage 
between the Rocky mountains and the Sierra Nevada. The majority of 
the minor basins in this region, however, are due to secondar}^ causes, 
but the vast seas, such as lakes Bonneville and Lahontan, which for- 
merly existed there, occupied basins of the character here referred to. 

The Laurentian lakes are held in basins produced in part by crustal 
movements affecting large areas, and in part by conditions resulting from 
other causes. Basins are also produced by less extensive elevations and 
depressions of the earth's crust. The corrugation of a region, owing to 
the formation of a series of approximately parallel folds, known as anti- 
clinals and synclinals, as in the case of the Appalachian mountains, nuist 
frequently produce basins in which water' would be retained, were the 
process allowed to go on without some counteracting agency ; but here 
again, the movements are usually so slow that, especially in humid regions, 
the depressions produced are destroyed as rapidly as they are formed. 
While lakes in synclinal basins might be expected to be of common occur- 
rence, they are in reality so rare that, so far as I am aware, none of the 
tens of thousands of the lakes of America can be pointed to as examples. 

There is still another variety of earth movements in many instances 
less gradual than those referred to above, to which many lakes owe their 
origin. 

Fractures in the earth's crust occur in disturbed regions and may be 
scores or even hundreds of miles in lenp-th. The edcjes of the broken 
strata on one side of a fracture are sometimes elevated, or those on the 
opposite side depressed, thus forming what is known as a "fault." The 
growth of faults sometimes goes on so slowly that no j)ronounced changes 
in topography result, for the reason that the rocks on the upheaved side 
of the fracture are eroded away as fast as they are raised. At other 
times, however, mountain ranges are produced, in which the strata are 
inclined awa}' from the steep, broken face overlooking the line of fracture. 
In regions where such mountain ranges have been formed with comparative 
rapidity and where denuding agencies are weak, great disturbances in the 
drainao-e result, and " fault basins " are common. Numerous basins of 



30 LAKES OF NORTH AMERICA. 

tliis character occur in the Arid region and especially in Nevada and 
southeastern California, but probably the most typical example is the 
one occupied by Abert lake, Oregon. 

Along the east side of Abert lake there is a long line of magnificent 
palisades, several hundred feet high, formed by the precipitous face of an 
eastward dipping fault block ; the lake washes the base of this escape- 
ment and occupies the depression formed by the subsidence of the rocks 
on the west side of the fracture. Something of the appearance of Abert 
lake, as seen from the crest of the palisades a few miles to south of its 
southern end, and also of the general structure of the underljdng rocks, 
may be gathered from the accompanying illustration. The lake is about 
fifteen miles long with an average width of nearly four miles, and is 
shallow. It receives the Avater of a single creek, but does not overflow 
and is intensely alkaline. 

Many of the lakes of the Arid region are of the Abert type, but 
usually the great depressions in which they occur have become deeply 
filled with the sediments of older water bodies, and they may be considered 
as occupying depressions on new land areas, or as belonging to the class 
of basins here considered, as one prefers. 

In some instances the faulting that gave origin to the characteristic 
topography of the Great Basin region has been continued to the present 
time, and produced escarpments across the bottoms of the deeply filled 
valleys, so that the existing water-bodies are confined in part by recent 
fault scarps. An instance of this nature is furnished by Mono lake, Cali- 
fornia, which washes the base of a precipice formed by a recent movement 
of the great Sierra Nevada fault. A similar association has also been 
observed in connection with several of the lakes of western Nevada. 

When a fault crosses the course of a river, the edge of the upturned 
block may rise so slowly that the stream is able to maintain its course 
and cut a channel through the obstruction as it is elevated, and a lake is 
not formed. Numerous instances of this nature have been observed by 
the writer in the central part of the state of Washington, where the 
Columbia and the Yackima river have eroded deep narrow gorges through 
the edges of fault blocks that were upheaved across their courses. 

With basins produced by faulting, as in other instances of surface 
inequalities due to movements of the earth's crust, the question whether a 
lake will be formed or not, is answered mainly by the climatic conditions. 
In arid regions the surface effects of orographic movements are counter- 
acted by erosion but slowly: while in countries with abundant drainage 



ORIGIN OF LAKE BASINS. 31 

degradation goes on energetically, and unless the deformation of the 
surface is comparatively rapid, no pronounced topographic changes result. 
It is the ratio between the rate of deformation and denudation which de- 
termines whether basins shall be formed or not. Evidently the most favor- 
able regions for studying the effects of movements in the earth's crust on 
the surface relief, are those in which the meteoric and aqueous agencies 
are least energetic, namely, in arid regions. 

Basins due to land-slides. — On steep slopes great masses of rocks 
and earth not infrequently break away, especiall}' after heavy rains, and 
descend suddenly as land-slides into the adjacent valley. When this 
occurs, the drainage in the valley may be obstructed so as to cause lakes 
to form. Avalanches of snow and loose rocks also produce similar results, 
but of a less pronounced character. 

Small lakes originate in many cases on the surface of land-slides 
owing to the fact that such surfaces, after the descending mass has come 
to rest, usually incline toward the cliffs from which they broke away, in 
such a manner as to enclose basins. At times, a land-slide plows up the 
floor of the valley into which it plunges and forms a ridge, not unlike a 
terminal moraine, which may also act as a dam and hold a lake in check. 
Examples of basins formed in each of these several ways have been 
examined by the writer in the state of Washington ^ and in other regions, 
but need not be described at this time. 

Basins due to chemical action. — In limestone countries the drainage 
is often subterranean and finds its way through caverns formed by the 
solution of the rock. The roofs of such caverns fall in as the general 
erosion of the region progresses, and o])struct the drainage channels so as 
to form lakes. The surface waters reach underground channels through 
openings termed "sink-holes," or " sAvallow-holes," which are enlarged by 
solution, and frequently become closed so as to hold ponds. In portions 
of Kentucky and throughout the Great Appalachian valley, wliere the 
underlying rock is limestone, circular ponds of this nature are so numer- 
ous that they give character to the landsca[)e. I-«akes also occur in the 
caverns themselves, owing to various causes, the most frequent being tlie 
falling of portions of their stalactic roofs, as may be seen in jMammoth 
and Luray caverns. 

^ "Geological Keconnoissanco in Central "\Vnshiiii.4on."' I'. S. Gool. Surv., Bulletin No. 108. 



32 LAKES OF NORTH AMERICA. 

Basins of small size, due to cliemical precipitation, occur in connection 
with springs that deposit calcareous tufa or siliceous cinter. Many ex- 
amples of pools formed in this way occur in the Yellowstone National 
Park and in other hot spring regions of the Cordilleras. Near the west 
shore of Mono lake, California, there is a castle-like bowl of calcareous 
tufa, fully 50 feet high and from 150 to 200 feet in diameter, with several 
long aqueduct-like branches, which was formed from the water of a spring 
that has now ceased to flow. Far out on the desert valleys of Utah and 
Nevada one sometimes finds circular basins with rims of tufa from a few 
inches to three or four feet high, and holding beautifully clear water with 
a temperature approaching the boiling point. In other instances, these 
deposits rise several feet above the adjacent surface and resemble volcanic 
craters. In their summits there are frequently steaming caldrons. 

In regions underlain by gypsum, rock salt, and other easily soluble 
substances, depressions are formed on account of the removal in solution 
of the rocks beneath and the subsidence of the surface. 

Gypsum is thought by some "geologists to owe its formation to the 
alteration of limestone by the passage through it of sulphurous gases or 
of sulphurous waters. When this occurs, the volume of the deposit is 
increased and the ground above may be elevated into mounds, and thus 
obstruct the drainage. 

CONCLUSION. 

In this chapter an attempt has been made to describe briefly the 
principal types of lake basins occurring in North America, to indicate the 
processes by which they have been formed, and to show to some extent, 
where they severally belong in the history of topographical development. 

Many basins have resulted from the action of more than one agency, 
and in not a few instances several agencies have cooperated in their 
production. Basins of a composite character have thus originated, but 
the principal cause leading to their existence is usually so pronounced 
that when carefully studied, they may without great violence be referred 
to some one of the types here described. 

The study of lakes has shown that they frequently have a long and 
varied history, which is no less interesting and instructive than the story 
of the origin and decadence of the hills that are reflected in their glassy 
depths. Some of the phases of their not uneventful lives are described 
in the succeedino- chaDters. 



CHAPTER II. 

MOVEMENTS OP LAKE ABATERS AND THE GEOLOGICAL 
FUNCTIONS OP LAKES. 

Tides. — The waters of lakes are influenced by the attraction of the 
sun and moon in the same manner as the waters of the ocean. Owing 
to the comparatively small extent of inland water-bodies, however, the 
rise of their waters is so small that it is not noticeable, and can only be 
determined by refined measurements. 

Observations made by the U. S. Lake Survey at Chicago, have shown 
that Lake Michigan has a tide with an amplitude of 11- inches for the 
neap tide and 3 inches for the spring tide. 

TVaves and currents. — The waters of fresh lakes respond to the 
influences of the wind more quickly than the heavier waters of the ocean, 
but the waves produced are smaller and less regular than in the open sea. 
On the Laurentian lakes, waves from 15 to 18 feet in amplitude have 
been observed during long continued storms. The heavy ground swell 
of the ocean is but faintly reproduced by the fresh water "seas." During 
rough weather on the lakes the waves are more like the short, " chop 
seas " than the heavy surges of the open ocean. 

The friction of the wind on the surfaces of lakes produces very decided 
movements in their waters. In their central portions, especially, there are 
frequently strong currents due to this cause, in addition to the slow 
movement of the waters toward an outlet. A study of the currents of 
the Laurentian lakes has been undertaken by the United States Weather 
Bureau, by means of bottles containing a record of the locality where 
they were set adrift and a request that the finder will note the locality 
where they are recovered and transmit the record to the Chief of the 
Weather Bureau. The results of observations made in the summer season 
of 1892 and 1893, have been published,^ and the general courses of the 
currents so far as ascertained, indicated on a chart which is reproduced 
on Plate 7. The effects of the prevailing westerly winds on the surface 
movement of certain of the Laurentian lakes, is indicated by the trend 

1 U. S. Department of Agriculture, Weather Bureau, IkiUelin B. 



84 LAKES OF NORTH AMERICA. 

of tlie principal currents. When the hirger axis of a lake coincides with 
the direction of the prevailing winds, a surface current is established 
through its center, as in the case of lakes Erie and Ontario, with return 
currents and eddies along the shore and about islands. When lakes lie 
athwart the prevailing winds the main currents combine with the return 
currents and form minor swirls, as is shown on the chart in the case 
of lakes Michigan and Huron. In Lake Superior there is a general 
circulation which follows the main shore lines, but its course has not been 
fully determined. It has been found that the currents of the Laurentian 
lakes have in general a speed of from 4 to 12 miles a day, but in certain 
observed instances, this is increased to 21- to 4 miles an hour or from 36 
to 96 miles a da}^ 

The currents in the central jDart of a lake produce slight if any 
changes on the topography of its basin, but when they follow the shore 
important results may follow. When the wind blows obliquely to the 
shore, strong currents are frequently produced which follow the general 
trend of the coast, but cut across bays and inlets. These currents, with 
the assistance of waves, sweep along sand and gravel, and produce impor- 
tant changes on the bottom, particularly^ when the Avater is shallow. The 
r81e played by waves and currents in modifying topography is considered 
Avith some detail in the next succeeding chapter. 

Strong winds blowing in a nearly uniform direction for several days 
cause the waters of lakes to move Avith them, and to rise on the shores 
against which they are driven, so as frequently to produce disastrous 
inundations. A gale blowing from the north over Lake Michigan has 
been observed to cause a rise of seven feet at Chicago. In NoA^em- 
ber, 1892, a storm from the AA^est caused the waters of Lake Erie 
near Toledo, to fall between eight and nine feet beloAv the normal fair 
weather level. At the same time, unusually high Avater Avas experienced 
at the east end of the lake. The cliff ei'ences in the level of the waters of 
Lake Erie, at Buffalo, 'be tAveen a high-AA^ater stage produced by an east^ 
ward blowing gale, and a loAA^-Avater stage accompanying a westAvard or 
off-shore gale, has been obserA'ed to amount to 151- feet. An eastward 
movement of the Avaters of Lake Superior has been known to accom- 
pany a gale from the west and to produce an unusual rise in the Avater 
of St. Mary's river. 

The height to AAdiich the waters reach on lake shores, OAving to strong 
Avinds, establishes the upper limit of wave-action, and leads to the forma- 
tion of storm beaches at an elevation of several feet above the normal 



MOVEMENTS OF LAKE WATERS. 35 

stage. When the shores of a lake are low, broad areas are inundatecl 
during storms that sweep the waters towards them. New outlets may- 
be established at such times across low divides, and lead to im^^ortant 
changes in drainage. 

Seiche. — Lake waters are also sensitive to changes in atmosj^heric 
pressure. In some instances variations of level during calm weather, 
amounting to several feet, have been observed, and are supposed to be due 
to sudden changes in barometric pressure on different jDortions of the 
water surface. Besides these larger movements, which can be correlated 
with atmospheric changes, and are known as seiches,^ there are certain 
rhythmical pulsations producing a difference of level of as much, as four 
or five inches during calms, when no variation in atmospheric pressure of 
an analogous character can be detected. These minor movements are 
not thoroughly understood. 

These and other changes of a similar nature are of great interest in 
connection with meteorological studies, but have little if any geological 
significance. 

It is to be expected that earthquakes would produce " tidal waves " in 
lakes similar to those occurring in the ocean, but observations in this 
connection are wanting. 

Temperature. — Lake Avaters are warmed by the sun's rays and by 
contact with the air. It has also been thought by some that very deep 
lakes may have their bottom temperatures modified by the general internal 
heat of the earth, but observations do not seem to support this conclu- 
sion. Water is a poor radiator and an indifferent conductor of heat, and 
does not respond to atmospheric changes of temperature as quickly as do 
rock surfaces. Shallow lakes are warmed throughout b}^ the summer's 
heat and chilled to the bottom by the winter's cold ; but their tempera- 
ture is much more uniform than that of the adjacent air. The shal- 
low lakes of the Northern states have been found to have a nearly- 
uniform temperature during the summer months of 75° Fahrenheit. In 
winter their temperature in general is, of course, 32° Fahrenheit. In 
lakes having a depth in excess of about 800 feet, more interesting condi- 
tions are found. The temperatures of deep lakes are ascertained by means 
of self-registering thermometers attached to sounding lines. In this 

^ E. A. Perkins. "The Seiche in American Lakes," American Meteorological Jour., 
Oct., 1893. 



36 



LAKES OF NOETH AMERICA. 



way accurate measurements of temperature at various deptlis liave been 
made in a number of lakes, both in America and in Europe, with remark- 
ably consistent results. Of the observations thus far made in this country, 
the most instructive are by Professor John Le Conte,^ in Lake Tahoe, 
California. From the report of these observations I quote the following : 

"These experiments were executed between the 11th and 18th of August, 1873. 
The same general results were obtained in all parts of the lake. The following table 
contains an abstract of the average results, after correcting the thermometric indications 
by comparison with a staiidard thermometer : 









Tempeeatuee. 


Obs. 


Depth ix Feet. 


Depth i>*^ Meters. 












Fahrenheit Scale. 


Centigrade Scale. 


1 


= Surface. 


= Surface. 


67° 


19.44° 


2 


50 


15.24 


63° 


17.22° 


3 


100 


30.48 


55° 


12.78° 


i 


150 


45.72' 


50° 


10° 


5 


200 


60.06 


48° 


8.89° 


6 


250 


76.20 


47° 


8.38° 


7 


300 


91.44 


46° 


7.78° 


8 


330 (Bottom) 


100.58 


45.5° 


7.50° 


9 


400 


121.92 


45° 


7.72° 


10 


480 (Bottom) 


146.30 


44.5° 


6.94° 


11 


500 


152.40 


44° 


6.67° 


12 


600 


182.88 


43° 


6.11° 


13 


772 (Bottom) 


235.30 


41° 


5° 


14 


1506 (Bottom) 


459.02 


89.2° 


4° 



"It will be seen from the foregoing numbers that the temperature of the water- 
decreases with increasing depth to about 700 or 800 feet (213 or 244 meters), and 
below this depth it remains sensibly the same down to 1,506 feet (459 meters). This 
constant temperature which prevails at all depths below say 250 meters is about 
4° C. (39.2° Fahr.). This is precisely what might have been expected; for it is a 
well-established physical property of fresh water, that it attains its maximum density at 
the above-indicated temperature. In other words, a mass of fresh water at the tempera- 
ture of 4° C. has a gTeater weight under a given volume (that is, a cubic inch unit 
of it is heavier at this temperature) than it is at any temperature either higher or 
lower. Hence, when the ice-cold water of the snow-fed streams of siDring and summer 
reaches the lake, it naturally tends to sink as soon as its temperature rises to 4° C. ; 
and, conversely, when winter sets in, as soon as the summer-heated surface-water is 

1" Physical Studies of Lake Tahoe," Overland Monthly, 2d Series, vol. 2, 1883, pp. 
506-516, 595-612 ; vol. 3, 1894, pp. 41-46. 



MOVEMENTS OF LAKE WATERS. 37 

cooled to -i^, it tends to sink. Any further rise of the temperature of the surface-^vater 
during the warm season, or fall of temperature during the cold season, alike produces 
expansion, and thus causes it to float on the heavier water below ; so that water at 
4° C. j)erpetually remains at the bottom, while the varying temperature of the seasons 
and the penetration of the solar heat only influence a surface stratum of aboiit "ioO 
meters in thickness. It is evident that the continual outflow of water from its shallow 
outlet cannot disturb the mass of liquid occupying the deeper portions of the lake. It 
thus results that the temperature of the surface-stratum of such bodies of fresh water 
for a certain depth fluctuates with the climate and with the seasons ; but at the bottom 
of deep lakes it iindergoes little or no change throughout the year, and approaches to 
that which corresponds to the maximum density of fresh water." 

Influence of lakes on climate. — Inland water bodies exert an impor- 
tant influence on the climate of their shores, in reference especially to 
temperature and humidity, and also on the direction and character of the 
more gentle winds. The surface waters of lakes receive their temperature 
in a great measure from the air in contact with them, and are warmed or 
cooled at rates having some relation to their depth. The temperature of 
shallow lakes varies but little from that of the adjacent atmosphere, but 
changes less rapidly for the reason, already stated, that water surfaces are 
poor radiators. The differences between the rates of radiation between 
adjacent land and water surfaces, affect the temperature of the air above 
them, and in calm weather give origin to lake and land breezes. 

The tens of thousands of small lakes scattered over the oiaciated 
portions of North America have an important combined influence on the 
general climate, although their effects may, perhaps, be difficult of direct 
determination. These lakes cool and moisten the atmosphere by evapora- 
tion during the hot summer months, and when they freeze as winter 
approaches, a vast amount of "latent heat" is liberated and moderates 
the fall in temperature. It is stated by physicists that every ton of water 
converted into ice gives out as much heat as would be required to raise 
the same quantity of water from 30° to 17-1° Fahrenheit. A reverse 
process, not so congenial to the welfare of man. takes place, however, 
when the ice melts in spring, as then an amount of energy equal to that 
previously lost, must be again absorbed in order that tlie ice may change 
to water. The warm southern winds are thus chilled and the opening of 
the flowers delayed. 

Deej) lakes, as already seen, have a uniform bottom temperature of 39 
degrees of the Fahrenheit scale, and do not freeze in winter except about 
their shores where the water is shallow, for the reason that tlie low 
temperature of the air above them dc^es not continue long enough for the 



38 LAKES OF NORTH AMERICA. 

entire water-body to become cooled to the degree of maximum density. 
Until this happens the water cooled at the surface from contact with the 
air, has its density increased and sinks, and is replaced by warmer and 
consequently lighter water, rising from below, and ice cannot form. 

The surface waters of deep lakes are thus above the mean temperature 
of the adjacent atmosphere in winter ; but in summer they are cooler than 
the air, as the warmed surface layer loses heat by conduction downward. 
The winds that blow over them are thus tempered in a manner congenial 
to the growth of vegetation both in warm and in cold weather. 

The influence of the Laurentian lakes on the climate of their shores 
is well marked, as was clearly shown many years since by Alexander 
Winchell.^ On charts that have appeared showing the winter and sum- 
mer isobar, that is, lines drawn through the various localities having the 
same mean temperature, the lines showing the mean summer temperature 
curve northward in the vicinity of Lake Michigan especially, while the 
lines indicating mean winter temperature present an equally marked 
southern curvature, showing that the lakes cool the air that passes over 
them in summer and warm it in winter. The genial influence of the 
lakes is also plainly to be seen in the distribution of the fruit-belts of 
Michigan, Ohio, and New York. 

If we should construct a map showing the mean humidity of the air, 
by drawing lines through the localities having the same " relative humid- 
ity," the influence of the lakes would be quite as apparent as in the case 
of the isothermal lines, but the curvature in both winter and summer 
Avould be southward. 

The amelioration of climate produced by large inland water-bodies 
has an important influence on the flora and fauna of their borders, and 
therefore on the character of the fossils entombed in their sediments. 
Another fact of geological interest in this connection, is that rocks decay 
more rapidly under warm, moist climates than in arid or in Arctic regions, 
and deeper and richer soils are produced. This, again, influences the 
life of lake regions, and is, perhaps, of sufficient importance to be con- 
sidered in interpreting the records of ancient inland water-bodies. 

Influence of lakes on the flow of streams. — Lakes act as storage 
reservoirs and regulate the flow of the streams, of which they are enlarge- 
ments. In the case of a river subject to sudden freshets, the disastrous 

i"The isothermals of the Lake Region," Am. Assoc. Adv. Sci., Proc, vol. IG, Troy- 
Meeting, 1870, pp. 106-117. 



MOVEMENTS OF LAKE WATERS. 39 

effects of a sudden rise would be checked, and even entirely averted, if 
a lake of sufficient size existed in its middle course, or if there were a 
number of lakes on its tributary streams. 

The modulating influence of lakes on the flow of streams is well 
known to hydraulic engineers ; and it has been proposed to regulate the 
flow of the Mississippi by building storage reservoirs on its head M^aters. 
Such reservoirs could be filled during floods and the water allowed to 
escape when the danger stage had passed. In this manner the disasters 
resulting from annual freshets could be averted and navigation improved 
durin2r the seasons of low water. 

The effect of gales in heaping up the waters of lakes on the shores 
against which they blow has already been noted, and an instance cited 
where the waters of St. Mary's river were suddenly raised by a gale on 
Lake Superior. A rise of the water in streams flowing from large lakes, 
due to this cause, is exceptional, however, and by no means as destructive 
as the fluctuations produced by storms and melting snow on water courses 
that are without the regulating influences of large lakes. 

The sudden escape of lakes held by dams of ice also causes floods in 
the streams below, as in the case already cited of the Rhone, when Milr- 
jelen lake is drained, and of the Stickeen, where the glacial-held lakes on 
its tributaries break their icy bands. 

The rise of Lake Bonneville until it found an outlet and then rapidly 
cut down its channel of discharge through unconsolidated material, as 
will be described in advance, is supposed to have caused a great rise in 
Snake river, to which it became tributary. In these and other waj'S that 
might be cited, it appears that lakes may cause floods in their draining 
streams as well as avert them. 

Lakes as settling- basins. — The streams flowing into lakes are fre- 
quently turbid and heavy with sediment, especially after storms, but the 
rivers flowing from them are usually clear and free from all but possibly 
the finest of material in suspension. During the slow passage of the 
Avaters through a lake wliich has an outlet, the material in suspension 
falls to the bottom and contiibutes to the filling of the basin, while the 
clarified waters flow on. 

The fact that bodies of standing w^ater retain the mineral matter 
Ijrought to them in suspension, is illustrated more or less perfectly in 
nearly every lake and pond, and even by ephemeral pools by the wayside, 
but is especially marked in great seas like those drained by the St. Law- 



40 LAKES OF NORTH AMERICA. 

rence. During storms, all of the streams pouring into the upper Lauren- 
tian lakes, from the surface drainage of the land, are brown and heavy 
with mud, but the water rushing over Niagara remains of the same deep 
greenish-blue tint season after season and year after year. Niagara river, 
above the falls, and the St. Lawrence are surface streams, because their 
clear waters have but slight power of corrasion ; it is for this reason that 
during the centuries they have occupied their present channels they have 
not materially deepened them. 

In the case of lakes fed by the turbid waters from, glaciers, the part they 
play as settling basins is even more strikingly shown than in the instances 
just cited. Lake Geneva, Switzerland, fed by the silt-laden waters of the 
Rhone, is discolored for several miles from where the river enters, but 
when the waters leave the lake and again start on their journey they are 
wonderfully clear. An abundance of similar illustrations are furnished 
by the glacial-fed lakes of the Sierra Nevada and Cascade mountains and 
by some of the numerous lakes on the head waters of the Yukon. 

The streams flowing from lakes are not always clear, however, as 
exceptions occur where the outlets are so situated that shore currents 
may bring sediment to them. The construction of beaches and embank- 
ments by shore currents may take place at the outlet of a lake so as to 
obstruct the escape of its waters and initiate a struggle between the 
waters tending to form deposits and those escaping through the channel 
of discharge. The outflowing waters may thus be rendered turbid and 
have the material supplied with which to erode their channels. A case 
in point is thought to be furnished at the south end of Lake Huron, 
where River St. Clair has its source, although definite observations on 
the relation of the outlet to shore currents have not been made. The 
waters of River St. Clair are not of the transparent character that would 
be expected in a stream starting from a large lake ; and a broad delta has 
been formed in Lake St. Clair, into which the liver empties after a short 
course through low alluvial lands. The source of the material forming 
the delta cannot be referred to the erosion of the banks of the stream, and 
is not furnished by tributaries, but apparently comes from the action of 
waves and currents on the shores of Lake Huron adjacent to its outlet.^ 

The rapidity with which lake basins in all parts of the world are 
becoming filled with sediment is sufficient in itself to show that no lakes 
fed by turbid streams can be geologically old. 

1 These conclusions have recently been confirmed "by F. B. Taylor in an instructive paper 
on "The Second Lake Algonquin," Am. Geol., vol. 15, March, 1895, pp. 171, 172. 



MOVEMENTS OF LAKE WATERS. 41 

Mechanical sediments. — Tlie coarse sediment brought to lakes by 
streams is either built into deltas or swept along the coast by shore cur- 
rents and mingled with the pebbles and sand derived from the wear of 
the land by shore waves. The finer products of the wash of the land, 
and of shore erosion, are carried lakeward and deposited in stratified lay- 
ers over the lake bottom. In general, the sheet of material thus spread out 
is tliickest and coarsest near shore and becomes finer and thinner as the 
distance from land increases. When sedimentation goes on uninterrupt- 
edly until a basin is filled, the result is a more or less regular lens-shaped 
body of sediments, having a broad central area of fine material, which 
graduates into a fringe of coarser character about its borders. The coarse 
strata in the shore deposits overlap and dovetail along their lakeward 
margins, Avith the outer borders of the layers of fine sediment in the cen- 
tral part of the basin, for the reason that the coarser material is carried 
farther from land during storms than when the weather is calm. This 
general relation of coarse shore and fine off-shore deposits is of interest, 
especially in the study of extinct lakes, and may enable one to draw their 
former boundaries with considerable accuracy even when all distinctive 
features of their shore topography have been obliterated. 

The sediments of the existing lakes of America, so far as they have 
been studied, are principally clays, which vary in character according to 
the nature of the rocks and soils on the neighboring land. The sediments 
of the Laurentian lakes and of lakes generally, particularly in humid 
regions, are characteristically blue clays. The Pleistocene clays of the 
Erie and Ontario basins are tenacious blue clays, similar to those now 
accumulating in the same basins ; but the clays deposited during a 
former broad extension of Lake Superior are fine, evenly laminated pink- 
ish clays, and owe their distinctive tint to the color of the rocks from 
which they were derived. 

The sediments now accumulating in the lakes of the arid regions, 
but more especially in the temporary or playa lakes, are usually light- 
colored, and have a yellowish tint when dry. 

In regions of deep rock decay, like the southern Appalachians, the 
debris swept into lakes would have the characteristic tints of terra rossa, 
as the highly oxidized product of prolonged rock decay is termed, unless 
it was mingled Avith organic matter in suificient quantity to deoxidize 
the iron to which its richness of color is due. 

The generalization that all lake sediments are of a reddisli tint, for- 
merly advanced by certain English geologists, does not find support from 



42 LAKES OF NORTH AMERICA. 

somewhat extended observations made in this connection in America. 
In fact, the blue and yellowish tints of such deposits are so general in this 
country that the reverse of the proposition referred to might be more 
reasonably claimed. 

In small lakes, when sedimentation is retarded, the growth of mol- 
lusks, diatoms, etc., may progress rapidly and their dead shells accumu- 
late on the bottom so as to exceed the amount of mechanical sediment, 
and shell marl and diatomaceous earth be formed. This process is 
especially well marked in lakes that are surrounded by matted vegetation 
through which the inflowing waters percolate and are filtered of nearly 
all material in suspension. As the growing mosses encroach on lakes of 
this character, a layer of peat is formed above the marl and a well-marked 
stratification results. Layers of peat above strata of shell marl may be 
seen in process of accumulation in many of the small lakes of Michigan 
and other similar regions. In lake and swamp deposits that are now 
drained and utilized for farming purposes, a layer of white marl beneath 
black humus, is frequently expose'd. These deposits have an additional 
interest from the fact that we find in them the bones of the mastodon, 
mammoth, giant beaver and huge sloth-like animals that roamed over 
North America in recent times, but are now extinct. 



CHAPTER III. 

THE TOPOGRAPHY OF LAKE SHORES. 

The variety and beauty of a landscape, embracing mountains and hills, 
valleys and ravines, is mainly due, as is well known, to the action of 
running water. The lines resulting from this mode of sculpture are more 
or less vertical. The waters of lakes also engrave their histories on the 
rocks, but the writing conforms with the water surface and is in horizontal 
bands. Two strongly contrasted types of relief are thus produced, which 
may be distinguished at a glance. The details in each type may be 
separated and their mode of origin explained. Each feature of the land 
is thus found to have a meaning, and the pleasure derived from even the 
most sublime and beautiful landscapes is vastly enhanced to those who 
can read their histories. 

The work of rain and rivers is outside the scope of the present book, 
but the principal topographic features characteristic of lake shores will be 
briefly described and their mode of origin indicated. 

The sea cliff. — Usually the first features of a lake shore to attract 
attention are the steep slopes which rise from the water's edge and seem 
to mark the boundary beyond which the waves cannot pass. That the 
slopes here referred to have been produced by the waters of the lake eat- 
ing into the land, is so apparent that it seems almost a waste of Avords to 
explain the process by which they are formed. Their declivity varies accord- 
ing to the nature of the material forming the land and also in conformity 
with atmospheric conditions. When the shores are of soft rock or loose 
unconsolidated material, the slopes are gentle, but when the shore is of 
hard rock they may become vertical or even overhanging precipices. In 
regions where weathering is progressing actively, the waste of the land, 
owing to the combined influences of rain, frost, etc., may be more rapid 
than the erosion of a lake shore by waves and currents; under these con- 
ditions the bluffs bordering a lake will have a more gentle slope than 
where atmospheric agencies are relatively less destructive. The name 
"sea cliff" is applied to tlie slopes jjrodueed by the under-cutting of lake 
shores without reference to tlieir declivity, and has been borrowed from 



44 LAKES OF NORTH AMERICA. 

the nomenclature of the oceanic shores where topographic forms similar in 
character and in origin exist in many places on a magnificent scale. Varia- 
tions in the appearances of sea cliffs in soft and hard material are shown on 
Plates 8 and 9. These illustrations have been selected from a large num- 
ber of photographs taken by the writer on the borders of the Laurentian 
lakes, and illustrate the two types of shore features there most pronounced. 
The recession of sea cliff's may be best studied when a gale is blowing 
directly on shore. At such a time, each wave as it reaches shallow 
water and surges up on the land, carries forward the gravel and sand 
within reach and dashes it against the base of the cliff and tends to 
wear it away. The finer products produced by the friction and pounding 
of the loose stones ao-ainst each other and ag'ainst the cliff, are carried lake- 
ward by the under-tow, leaving the coarser fragments ready to be caught 
up by the next inrush of water and the process repeated. As the cliff is 
under-cut, fresh angular fragments fall from its face to the beach below 
and are at once attacked by the waves ,and sooner or later reduced to 
rounded gravel and sand. The cliff thus furnishes the tools for its own 
destruction. 

The manner in which lakes 

,,-«^r wear away the land confining- 

^,--^P^ them is illustrated in the fol- 

.JidJ^f..±<^^fA9£ a^^^^s^^ lowing;' section of a rocky shore, 

^^^^^P^ which also shows the relation 

^^^^^^^^^^^^^ of the oea cliff h c to the 

platform or terrace a c at its 

Fig. 2. — Profile of a Sea Cliff and Terrace. , 

base. 

"Waves are only able to reach the land in a narrow vertical interval, 
determined mainly by the difference in their height during calm weather 
and when storms are raging. Even in the case of large lakes this inter- 
val does not exceed ten or fifteen feet, and on account of the debris 
usually enctimbering the shore, the actual zone of erosion on the fresh 
rock surface is normally very much less than this. The waves thus act 
like a horizontal saw cutting into the land. The result is that at the 
base of every sea cliff there is a platform or terrace, as indicated in the 
above diagram. The junction of the sea cliff with its accompanying ter- 
race is a horizontal line, determined by the elevation of the lake surface. 

Lake waters unaided by debris, like the waters of clear streams, have 
but slight power to erode. It is only when the margin of a lake is suffi- 
ciently shallow to bring the debris on its bottom within the reach of the 



THE TOPOGRAPHY OF LAKE SHORES. 45 

waves that the hind is cut away so as to fomi sea cliffs and terraces. 
This is shown in a striking manner along large portions of the shores of 
Lake Superior, where bold cliffs, an inheritance from a previous topo- 
graphic cycle, plunge into deep water, and are without talus slopes or- 
other loose deposits within reach of the waves. In these instances there 
is scarcely a mark on the rocks that would record the present horizon of 
the lake should its waters be Avithdrawn. Clear waters may dissolve the 
rocks against which they dash, however, and when cliffs of limestone 
and other easily soluble rock descend into deep waters, a line of grottoes 
and caves may be formed below the upper wave limit, and perhaps increase 
until a shelf is produced on which sand and pebbles could lodge. When 
this happens, erosion by solution is assisted by mechanical means, slight at 
first, but increasing as the conditions become more favorable, until cliffs 
and terraces result. 

Terraces. — The terraces about the margins of existing lakes are 
usually covered with the loose stones and sand, and form the beaches on 
which one may walk during calm weather. 

The surface of a typical lake terrace slopes gently lakeward and is 
bounded on the landward margin by the upward slope of the accom- 
panying sea cliff, and on the submerged, lakeward margin by a down- 
ward slope leading to deeper water. These terraces owe their formation 
to excavation or to deposition, and in most instances the two processes 
are combined. Even when the terrace is due principally to excavation, 
there is a surface layer of rounded debris resting on it, which is usually 
thickest on the lakeward margin and forms the lakeward slope. These 
features are shown in the following cross section of a lake shore, where a 
compound terrace is being formed, and also on Plate 13. 



LAKE SURFACE 




Fig. 3. — Profile of a cut and built Teurace. 

On precipitous, rocky shores, terraces are not produced, for the reason 
already stated in considering the origin of sea cliffs, that the debris from 
the land falls into deep water below the reach of the waves. 



46 LAKES OF NORTH AMERICA. 

Reference has already been made to tlie action of the waves when the 
wind blows directly on shore. The retnrn current is then an undertow 
flowing lakeward. When the Avind blows against the shore at a low 
angle, however, currents are established which travel along the lake 
margin and sweep the loose material on the surface of the terrace with 
them. These currents have many of the features of streams, and greatly 
increase the power of waves to erode the land. The upward movement 
of waves tends to lift loose material Avithin their reach and the lateral 
movement of currents to transport it. The loose material at the base of 
sea cliffs is thus carried along the beach by shore currents in one direction 
or another, according to the direction of the wind, and deposited so as to 
form accumulations of various character. 

When a headland, with a beach at its base, is flanked on either hand 
by low shores, the debris falling from its face is carried along by the 
shore currents and built into terraces adjacent to the land or deposited so 
as to form free embankments or ridges, at some distance from the original 
shore. That this process is of common occurrence may be shown on 
many lake margins by examining the material forming rocky headlands 
and comparing it with the stones on neighboring beaches. In such in- 
stances the rock fragments at the base of the cliff Avill frequently be 
found to be large and angular and to become smoother and more and 
more rounded the farther they are traced from their parent ledges. 

Terraces and marginal embankments, built wholly of gravel and sand, 
may also be formed on low shores by the washing up of loose material 
from this lakeward margin, thus deepening the water on the outside of 
the shelf. 

The transportation of debris along the surfaces of terraces by the com- 
bined action of waves and currents, and its deposition when deep water is 
reached, leads to the formation of structures of various forms, known as 
embankments. 

Embankments. — This name has been adopted for free ridges of 
loose material built by currents about the margins of water-bodies. They 
have the general form of railroad embankments, and their level crests in 
most instances rise from a few inches to, perhaps, three or four feet above 
the calm-weather surfaces of the Avater in Avhich they occur. The ten- 
dency of built terraces to change to embankments on low shores has already 
been noticed, but the most typical examples occur Avhere shore currents, 
having an abundance of loose material at their command, are deflected 



THE TOPOGRAPHY OIT LAKE SHORES. 



47 



into deep water and thus lose their power to transport. The variations 
in the shapes of embankments have led to the recognition of various more 
or less specific forms, such as spits, loops, bars, V-bars, etc., some of which 
are described below. 

The building of embankments can be best studied where there is an 
abrupt change in the direction of the shore adjacent to a locality where 
the formation of a sea cliff and its accompanying terrace is in progress. 
Such an instance is illustrated in the following sketch-map : 



^ir-i. 



'"■ -^- f'-^ 




Fig. 4. — Sketch-map of aji Emb.4J\kment. 

The shore on the right of the cove is steep and forms a sea cliff that rises 
above a terrace along which the current travels in the direction indicated 
by an arrow. Shore currents follow the broader outlines of the land, but 
cut across bays and inlets. For this reason, in the case before us, the 
sand and gravel swept along the surface of the terrace is carried into 
deep waters and is deposited when the direction of the shore changes 
abruptly, as the iiow of the water is then checked. The terrace is pro- 
longed as an embankment, having the same level, and is lengthened by 
material carried along its surface and deposited at its distal extremity. 
The construction of such an embankment is analogous to the manner 
in which railroad embankments are made by carting dirt along them 
from a cut and dumping it at the end of the unfinished structure. In 
cross sections an embankment shows a more or less perfect arching of the 
material, and forming what may be termed an " anticlinal of deposition." 

In the ideal illustration here presented, it is evident that a continu- 
ation of the process would result in the prolongation of the embankment 
until it touched the shore at the left of the bay. The outline of the lake 
would then be simplified and a lagoon formed behind the embankment. 
Should a stream enter sucli a lagoon, the water escaping from it might 
keep a channel open to the lake, but a struggle would ensue between the 
shore currents tending to close the break and the outflowing water 
striving to keep it open. Eddies in the conflicting currents would result 
and lead to changes in the outlines of the embankment. 



48 



LAKES OF NORTH AlVrERICA. 



When a structure like that described above is incomplete and projects 
from the shore like an unfinished railroad embankment, it is termed a sjnt. 
An illustration of such an instance observed on the shore of Au Train 
island, Lake Superior, is shown in Plate 11. See also Plates 2, 3 and 4. 

When an embankment 
spans the entrance of a bay 
so as to shut it off more or 
less completely from the 
main water body, it is 
termed a har^ in accord- 
ance with the custom of 
mariners in desiofnating" 
such obstructions to navi- 
gation. Maps of bars on 
the shores of lakes Su- 
perior and Ontario are re- 
produced in Figs. 5 and 
6, from the maps of the 
U. S. Lake Survey. The 
manner in which these 
were formed, as well as 
their various modifications 

FIG. 5. -MAP OF SA>-D B.^S : WEST EXD OF LAKE SUPERIOK. ^f ^^^^J- ^^^ ^^^^^ ^|^g preSCUCC 

of channels across them in certain instances, will be understood from the 
description of a more simple example just given. 

The end of a spit is frequently turned toward the shore, owing to a 
deflection of the current that built it, or to the opposing action of two 
or more currents, and becomes a hook, as is illustrated on Plate 12. 
Again, where the hook is more j^ronounced and the distal end of the 
structure touches the shore, as happens occasionally when there are only 
slight changes in the direction of the coast line, a hop-bar or V-har results. 

In brief, it may be said that the waves and currents of lakes have 
the power of excavating cut terraces along the shores confining them and 
of carrying away the waste from the cutting, together with similar mate- 
rial contributed by streams, and of building it into terraces and embank- 
ments of various forms adjacent to neighboring shores. 




Deltas. — Where streams bring to a lake more detritus than is carried 
away by shore currents, accumulation takes place and an addition, termed 



H 




THE TOPOGRAPHY OF LAKE SHORES. 



49 



a delta, is made to the land. The most instructive deposits of this nature 
occur where high grade streams enter a lake, as when a lake washes the 
base of a mountain range. In such an instance, pebbles and water-worn 
boulders are swept along by the stream until it mingles with the quiet 
lake water, where its velocity is checked and the coarser portion of its 




Fig. 6. — Map of sa^tj baes : South shore of Lake Ontario, 



load dropped ; fine sand is carried beyond and deposited about the outer 
margin of the accumulation of boulders and pebbles, and the finer 
material held in suspension is transported still farther from shore and dis- 
tributed over the lake bottom. The coarse material is deposited about 
the mouth of the stream in a semi-circular pile, the base of which is 
beneath the water and the apex some distance above, where the stream 
begins to lose velocity. The pile is built out in all directions in which the 
water has freedom to flow, and a semi-circular or occasionally a truly 
delta-shaped addition is made to the land. 

Fine examples of deltas, built by swift streams adjacent to a precipi- 
tous shore, occur on the west side of Seneca lake. New York, near Wat- 
kins. In these deltas the action of shore currents from both the north 
and south is conspicuous, and the deposits have been cut away so as to 
leave a triangular or markedly delta-shaped outline, but the apex of each 
" delta " points lakeward, instead of to\\iu'd the shore as is the normal 



50 LAKES OF NORTH AMERICA. 

condition. About the margins of these deltas there are small gravelbars 
that are frequently looped and enclosfe lagoons. An active struggle is 
there in progress between the outflowing streams and the shore currents, 
which has modified the form of the deltas in the peculiar way just 
referred to. 

A delta advances as fresh material is added to its outer margin, and 
at the same time the apex of the pile rises and slowly migrates up stream. 
.Such a deposit has a well-defined structure, due to its mode of growth. 
A radial section made from its apex to any point on its periphery would 
show three divisions, as is indicated in the following sketch section of a 
delta built in Lake Bonneville, at Logan, Utah. 




Fig. 7. — Section of a Delta. 

The history to be read in such a section is this : the fine, evenly strati- 
fied beds beneath the coarse inclined layers are sediments deposited on 
the lake bottom, but about the margins of deltas they are usually thicker 
than on neighboring lakeward areas, owing to more rapid depositions 
from the waters of the delta-forming stream. In some instances a broad, 
low apron-like deposit of fine sediment is formed about the lakeward 
margin of the delta proper. As the coarser portion of a delta increases, it 
advances lakeward and covers the layers of fine sediment previously laid 
down, and frequently causes them to become folded and wrinkled and 
occasionally broken and faulted, on account of the weight of material 
imposed upon them. 

The boulders, gravel and sand brought down by a stream are carried 
to the outer margin of its delta, and roll and slide down its submerged 
lakeward slope so as to form inclined layers. The angle of inclination 
of these layers is the angle of stability in water of the material forming 
them. Where the deposit is mainly of rounded stone and gravel, the 
angle of slope is in the neighborhood of 30 to 35 degrees, but ill some 
instances is steeper and the structures are unstable and favorable for 
landslides. 

The triangular area shown in the section, above the inclined beds, is 
the subaerial portion of the delta, built by the stream in meandering 




||M|fl|i||l|.pi|lYn||miijl 



::'i|p|i|»!ll!il|!!]lj|ii 




THE TOPOGRAPHY OF LAKE SHORES. 51 

over its surface. It is really an alluvial cone, similar to the conical piles 
of debris so common in desert valleys at the mouths of high grade canons. 
It is irregularly stratified, the layers being inclined at a low angle corre- 
sponding with the slope of the surface of the structure at the time they 
were laid down. 

The change from the gently sloping and irregularly bedded material 
of the alluvial portion or cap of the delta, to the steeply inclined and more 
regularly bedded layers, marks the level of the lake in which the deposit 
was formed. The outer margin or periphery of the delta, is in a horizon- 
tal plane and retains the same position as the delta advances, providing 
there is practically no change in the level of the lake surface. The surface 
slope of the cap of the delta, along radial lines from the apex to the periph- 
ery, is gently concave to the sky. On recent examiDles the surface is 
frequently scored with radiating and branching channels, or "distribu- 
taries," left by the changeable stream that built the structure. As a 
delta increases in size its apex rises and slowly migrates up stream, as 
already stated, so that in large deltas of high-grade streams the apex is 
frequently well within the mouth of the caiion through which the drain- 
age is delivered. 

In the deltas of low-grade streams, like the Mississippi, the divisions 
noted above are not readily distinguishable, as the material forming them 
is fine throughout and the inclination of all the layers is gentle. 

Should the surface of a lake be lowered after having stood at a definite 
horizon for a long period, the terraces, embankments, deltas, etc., formed 
about its borders become conspicuous features of the exposed land surface 
and another series of similar forms is at once begun at a lower level. 
Should another subsidence follow, another series of horizontal lines Avill 
be added to the topography of the shores. A rise of a lake causes 
the submergence of previously formed shore features, and they may be- 
come covered with fine sediment or have other wave and current-built 
structures imposed upon them. Such changes lead to puzzling compli- 
cations in the records, as has l)een observed in many instances where lake 
basins have been emptied and their sides and bottoms laid bare. 

Ice-built walls. — In addition to the topographic features character- 
istic of lake shores thus far noticed, there are others due to the action of 
ice. In northern latitudes the formation of sea cliffs, terraces, endxink- 
raents, etc., about the margins of lakes, excepting those of large size, 
takes place maiidy in the summer season. In winter. aaIkmi most small 



62 LAKES OF NORTH AMERICA. 

lakes are frozen over, the expansion of the ice pushes up stones and 
gravel along shelving shores and forms other topographic features. 
Another process tending in part in the same direction comes into play 
in the spring when the ice on a lake becomes broken and is moved 
by the wind. The action under these conditions is the same that takes 
place on a much larger scale on the shores of Labrador and other 
northern lands, Avliere an ice pack is driven on a shelving beach by 
the force of the wind. Stones and boulders are carried up low lake 
shores, in the manner here noted, and added to the ridge formed by 
the winter expansion of the ice. Occurrences of this character have 
been observed by J. B. TyrroU on the shore of Lake Winnipegasie.^ In 
some instances these ice-built ridges are so marked and appear so much 
like artificial walls that they are commonly referred to the work of man. 
In some observed examples in the northern portion of the United States 
and in Canada, ice-built ridges occur 40 to 50 feet from the water's edge, 
are 20 feet high and broad enough to furnish convenient roadways. 

The formation of ice-built waifs about the margins of small northern 
lakes by ice expansion was first explained by C. A. White.^ The process 
has also been clearly stated by Gilbert,^ in his treatise on the topography 
of lake shores, from which the folloAving is quoted : — 

" The ice on the surface of a lake expands while forming so as to 
crowd its edge against the shore. A further lowering of temperature 
produces contraction, and this ordinarily results in the opening of ver- 
tical fissures. These admit the Avater from below and by the freezing of 
that water are filled, so that when expansion follows a subsequent rise 
of temperature the ice cannot assume its original position. It conse- 
quently increases its total area and exerts a second thrust upon the shore. 
When the shore is abrupt the ice itself yields, either by crushing at the 
margin or by the formation of anticlinals (upward folds) elsewhere ; but 
if the shore is gently shelving, the margin of the ice is forced up the 
declivity and carries with it any boulders or other loose material about 
which it may have frozen. A second lowering of temperature does not 
withdraw the protruded ice margin, but initiates other cracks and leads 
to a repetition of the shoreward thrust. The process is repeated from 
time to time during the winter, but ceases with the melting of the ice in 
the spring. The ice formed the ensuing winter extends only to the water 

1 Geol. and Nat. Hist. Suvv. of Canada. Ann. Kep., 1800-91, p. 04 B. 
- American Naturalist, vol. 2. 1800, pp. 140-140. 

3 Fiftli Ann. Rep., U. S. Geol. Surv., p. 100. 



THE TOPOGRAPHY OF LAKE SHORES. 53 

margin, and by the winters oscillation of temperature can be thrust land- 
ward only to a certain distance, determined by the size of the lake and 
the local climate. There is thus for each locality a definite limit bej'ond 
which the projection of boulders cannot be carried, so that all are de- 
posited along a common line where they constitute a ridge or wall." 

Shore walls are not conspicuous about the margin of large lakes for 
the reason that the}' seldom freeze over and also because the winter's ice 
work is usually obliterated by the more active waves and currents at 
other seasons. They are not formed about deep lakes for the reason that 
such water bodies do not become ice-covered, and for the same reason 
they do not occur in warm climates. 

In this brief sketch of the topography of lake shores, an attempt has 
been made to direct attention to the main processes l^y whicli the results 
have been reached, and to describe briefly the character of some of the 
more striking forms produced, without attempting an exhaustive analysis 
of the subject. To the reader who would go farther in the studies here 
outlined, I most heartily recommend G. K. Gilbert's attractive paper on 
the topography of lake shore, in the 5th Annual Report of the U. S". Geo- 
logical Survey, and the more special volume by the same author on Lake 
Bonneville, forming ^Monograph No. 1 of the publications of the U. S. 
Geological Survey. 



CHAPTER IV. 

RELATION OF LAKES TO CLIMATIC CONDITIONS. 

Lakes may be conveniently divided into two great classes, fresli and 
saline, in reference to the chemical composition of their waters. These 
two classes have no sharply defined boundary between them, but a com- 
plete graduation may be found betAveen the freshest and most saline 
examples. 

A convenient test for determining to which class a lake should be 
referred is to taste its water. If no saline or alkaline taste is perceptible, 
it evidently falls in the first class ; but if the presence of salts can be 
determined in this way, it should be referred to the second class. 

It is frequently convenient, however, to recognize an intermediate 
class, or brackish-water lakes, to include water bodies that are slightly 
saline or alkaline to the taste, but contain only a small fraction of one 
per cent of mineral matter in solution. 

The more pronounced differences in chemical composition, shown by 
lakes, depend mainly on climatic conditions. Fresh water lakes overfloAV 
or else their surplus water escapes by percolation, while saline lakes are 
Avithout outlets. Exceptions to this rule may occur, but they are accom- 
panied by unstable conditions, and the presence of an outlet to a saline 
lake or its absence in the case of a fresh lake, are temporary phases that 
have not continued long enough to bring about the changes toward 
which they tend. 

Fresh lakes occur principally in humid regions, while saline lakes, 
with the exception of those formed by the isolation of bodies of sea 
Avater, are confined to regions of small rainfall. Whether a lake shall 
OA'erfloAV or not, depends ordinarily on the relation of the rainfall over its 
hydrographic basin to evaporation from the lake surface. As lakes fre- 
quently receive the AA^ater of fissure springs, the sources of which may be 
far distant, it Avill be more exact to say that whether a lake held in an 
imperA^ous basin shall overfloAv or not, depends on the ratio of the amount 
of water contributed to it to the amount cA^aporated from its surface. If 
the infloAA^ is in excess of evaporation, the AA^ater Avill rise and its area 
increase until an equilibrium is established or until an outlet is found. 



EELATIOX OF LAKES TO CLIMATIC CONDITIONS. 55 

When evaporation counterbalances the inflow for a long period, the 
waters are concentrated and become charged with mineral matter, for the 
reason that all streams and springs contain foreign substances in solution 
which are left when evaporation takes place. 

It has been found by observation that in regions where the topographic 
conditions are favorable, a rainfall of about 20 inches per year, and an 
evaporation from lake surfaces in excess of 50 inches per year, is fre- 
quently accompanied by the formation of lakes that do not rise suflicientl}' 
to find an outlet. When the difference in the direction indicated between 
precipitation and evaporation is still greater, or when the area from wliieh 
a lake receives the drainage is small in reference to the area where a lake 
would naturally form, desiccation may be complete and permanent lakes 
rendered impossible. 

Whether a lake shall be fresh or saline depends, therefore, on climatic 
conditions and on the configuration of its hydrographic basin. 

Fresh Lakes. 

Material in Solution. — As all fresh lakes ma}^ be considered as 
the expansions of streams, their chemical composition is indicated where 
the actual lake waters have not been analyzed, by the composition of the 
streams flowing to or from them. It follows, therefore, that the average 
composition of the waters of fresh lakes would be shown with consider- 
able accuracy, by the average composition of . the principal rivers in the 
region where they occur. 

Analyses of the waters of 20 of the principal rivers of the United 
States have shown that they contain on an average 0.15044 part per 
thousand of total solids in solution, of which 0.056416 part per thousand 
is calcium carbonate. This may be taken as the average composition of 
the fresh lakes of this country, but more particularl}' of those in the 
humid regions. 

In a table of 48 analyses of European river waters given in Bischof's 
Chemical Geology, the average of total solids in solution is 0.2127 and 
the average of calcium carbonate 0.1139 part per thousand. From the 
analyses of the waters of 36 European rivers given in Roth's Chemical 
Geology, including some of those mentioned by Bischof, the average of 
total solids is 0.2033 and of calcium carbonate 0.09598 part per thousand. 

In both American and European rivers, as determined from the above 
data, the average of total solids in solution is 0.1888 and of calcium car- 



56 LAKES OF NORTH AMERICA. 

bonate 0.088765 part per thousand. These figures may be safely as- 
sumed to represent the average amount of impurities carried by normal 
streams, and consequently indicate the character of the lakes to or from 
which they flow. The drainage in mountainous regions, especially where 
supplied by melting snow and ice, niiij be purer than these figures indi- 
cate ; while in arid regions, where efflorescent salts frequently whiten the 
surface, the streams are more highly charged with saline matter than when 
the rainfall is abundant. It is to be observed that material carried by 
streams in suspension is not included in the above considerations. 

The reader may, perhaps, conclude from the figures just given that 
the percentage of saline matter carried in solution by ordinary streams is 
unimportant and of but little significance in connection with the study 
of lakes. It is true that the amount of foreign matter in solution in a 
few gallons of river water is small, but where the volume of rivers is con- 
sidered the amount of solid substances carried by them in solution, even 
in a single jeai\ becomes truly startling. Knowing the volume of a 
stream and the percentage of mineral matter it contains, one can readily 
compute the weight of the matter it carries in solution in a definite time. 
This computation has been made for a few American rivers.^ 

The average flow of Croton river. New York, is 400,000,000 gallons 
daily. In this volume of water there are 183 tons of mineral matter in 
solution, of which 47 tons are calcium carbonate. 

The Hudson carries daily about 4,000 tons of matter in solution, of 
which more than 1,200 tons are calcium carbonate. 

The jNIississippi carries to the Gulf of Mexico in a single year about 
113 million tons of mineral matter in solution, of which over 50 million 
tons are calcium carbonate. 

These estimates are only approximately correct as they depend in 
most instances on a single analysis and on a small number of measure- 
ments of volume. 

The invisible loads carried by rivers are not only of interest in con- 
nection with the study of lakes, more especially of saline lakes, but open 
a wide field of research in reference to the chemical denudation of the 
land, the composition of ocean waters, and the source of the material, 
more particularly of the calcium carbonate, secreted by marine plants and 
animals. Into this broader domain, however, to which our subject leads, 
we may not now enter. 

1 The data from which the facts here stated were obtained, as well as similar information 
concerning otlier streams, is given in ^Monograph No. 11, U. S. Geol. Surv., pp. 172-175. 



eelatiox of lakes to climatic conditions. 57 

Types of Fresh Lakes. 

Of the tens of tlioiisands of fresli lakes scattered over North America, 
and especially abundant in the previously glaciated, northeastern por- 
tion of the continent, or forming a part of the more impressive scener}^ 
of the Cordilleran region, many might be selected as types. Atten- 
tion will be confined, however, to the Great Lakes, drained by the St. 
Lawrence, Lake Tahoe, California, and Lake Chelan in the State of 
Washington. 

The liaui-eiitian lakes. — The group of great lakes drained by the 
St. Lawrence, as is well known, contain the most magnificent examples 
of fresh water-bodies now existing on the earth. Lake Superior still 
retains its position as the largest sheet of fresh water known, although 
the more recent discovery of Lake Victoria Nyanza has brought a rival 
into the field. This African lake is estimated to have an area of about 
18,000 square miles, Avhich is 12,000 square miles less than the area of 
the great American lake ; but when an actual survey shall have been 
made, it is possible that this difference will be materially decreased. 

While Lake Superior exceeds all other fresh lakes in extent, it ranks 
second among terrestrial water-bodies, for the reason that the Caspian 
Sea is the largest sheet of water not in open communication with the 
ocean, now existing. The Caspian is saline, however, and falls in the 
second great division of lakes here recognized. 

The origin of the basins of the Laurentian lakes has been referred to 
in Chapter I. in connection with the action of glacial agencies in obstruct- 
ing drainage ; an account of their past history is given in advance in dis- 
cussing the Pleistocene lakes of the same region ; at present attention 
will be confined to some of the more interesting features of the existing 
lakes. 

The U. S. Lake Survey. — A survey of the Laurentian lakes was 
made by the Corps of Engineers, U. S. Army, between 1841 and 1881, 
and is known as the U. S. Lake Survey.^ On the maps or chart published 
by that survey, the outlines of the shores of the lakes and of their con- 
necting waters are given, together with the topography of a narrow strip 
of the adjacent land ; the depth of water, character of bottom, etc., as 

1 Report upon the Primary Triangulation of the U. S. Lake Survey, by Lieut.-Coh C. B 
Comstoek, AVashington, 1882. 



58 



LAKES OF jSTOETH AMERICA. 



determined from thousands of soundings, is also indicated. This excellent 
survey is the basis of nearly all accurate information noAV accessible con- 
cerning the phj^sical features of tlie lakes in question, and has been freely 
used in compiling the following statements. 

Owing to changes in the rivers connecting the various Laurentian 
lakes and in bays and navigable channels, and also on account of the 
many harbor and canal improvements that have been made, a new survey 
of portions of these lakes has been found necessary, and is now in i3rog- 
ress under the direction of Gen. O. M. Poe. 

The area of the Laurentian lakes has been determined with approxi- 
mate accuracy from measurements made on the maps of the U. S. Lake 
Survey. The results of these measurements by different individuals 
vary somewhat, but those published by L. Y. Schermerhorn^ are here 
adopted. 



Area of the Laurentian Lakes in Square Miles. 



Watee Sur- 
face. 



Water Shed. 



Hydeographic 
Basin. 



Lake Superior 

St. Mary's river 

Lake INIichigan 

Lake Huron and Georgian Bay 

St. Clair river 

Lake St. Clair 

Detroit river 

Lake Erie 

Niagara river 

Lake Ontario 

Total 



31,200 

150 

22,450 

23,800 

25 

410 

25 

9,960 

15 

7,240 



95,275 



51,600 
800 

37,700 

31,700 
3,800 
3,400 
1,200 

22,700 
300 

21,600 



174,800 



82,800 
950 

60,150 

55,500 
3,825 
3,810 
1,225 

32,660 
315 

28,840 



270,075 



The volume of Avater flowing through the rivers draining the various 
lakes is on an averao-e as f oIIoavs : 



St. Mary's river, the outlet of Lake Superior 

St. Clair river, the outlet of Lakes Huron and Michigan 

Niagara river, the outlet of Lake Erie 

St. Lawrence river, the outlet of Lake Ontario 



Cubic Feet 
TEK Second. 
86,000 
235,000 
265,000 
300,000 



1 "Physical Features of the Northern and Northvrestern Lakes," Anier. Jour. Sci., 3d 
sec, vol. 33, 1887, pp. 278-284. 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 



59 



The mean elevation of the surfaces of the Laurentian lakes above the 
sea, their maximum depth, etc., as shown by soundings, are as follows : 

Meax Elevatiox and Maximum Depth, etc.. of the Laurentian Lakes. 





jNIeax Eleva- 
tiox. 


Al'PROXIMATE 

jNIeax Depth. 


Maxijutm 
Depth. 


Depth of 

Basix Below 

Sea Level. 


Lake Erie 

Lake Huron .... 
Lake Michigan . . . 
Lake Ontario .... 
Lake Superior .... 


573 

5S1 
581 
247 
602 


70 
250 
325 
300 
475 


210 
730 

870 

738 

1.008 


149 

289 
491 
400 



The average discharge of the lakes is stated by Schermerhorn to be 
double that of the Ohio and nearly equal to one half the discharge of the 
Mississippi. The area of the Laurentian basin is a third larger than the 
hydi'ographic basin of the Ohio, or about a fifth of the combined areas 
of the basins of the jNIississippi and its affluents. The outflow of the St. 
Lawrence basin is slightly less than half its rainfall, while on the Missis- 
sippi and Ohio the discharge is about a fourth of the rainfall. If the 
average discharge of the Laurentian lakes passed through a river one mile 
wide Avith a mean velocity of one mile per hour, such a river would have 
a depth of 40 feet from shore to shore. 

The volume of water in the Laurentian lakes is about 6,000 cubic 
miles, of which Lake Superior contains somewhat less than one half. 
Perhaps a better idea of this volume may be obtained when it is said that 
it is sufflcient to sustain Niagara falls in their present condition for about 
100 years. 

The mean annual rainfall of the St. Lawrence basin is about 31 
inches ; and the mean depth of water evaporated from the surfaces of the 
lakes, between 20 and 30 inclies.^ The amount of precipitation on the 
water surface is, therefore, nearly compensated by the amount evaporated 
from the same area. 

Clu'inistry of the Avatcrs of the St. Lawrence. — The composition 
of tlie waters of the Laurentian lakes is shoM'n \\'itli approximate accuracy 



1 Thomas Kussell. " Deptli of Evaporation in lliu United States," Monthly Weather 
Report, U. S. Signal Office, Sept. 1888. 



60 



LAKES OF XOETH AMERICA. 



by an analysis of the water of St. Lawrence river taken near Montreal. 
This analysis may also be considered as representing very nearly the com- 
position of the material carried in solution by the lakes and rivers of the 
more humid portions of North America.^ 

AXALI'SIS OF THE "WaTER OF St. LaWRENCE RiVER. 
By T. Sterrt Hunt.^ 



IXGEEDUEXTS. 


Paets IX A Thousand. 


Sodium, N^a 


.00513 
.00115 
.03233 
.00585 
.00242 
.06836 
.00831 

trace 
.03700 

trace 

a 
a 


Potassium, K 


Calcium, Ca 

Magnesium, Mg 

Chlorine, CI 

Carbonic acid, CO3 


Sulphuric acid, SO, 


Phosphoric acid, HPOr 


Silica, Si02 ~- . . . . 

Alumina. ALOo 


' Z 

Oxide of iron, FeO 


Oxide of Manganese, MnO 

Total 


0.16055 





Taking the volume of the St. Lawrence at 300,000 cubic feet per 
second, the computed discharge of Lake Ontario, it follows from the above 
analysis that approximately 1.5 tons of mineral matter in solution is trans- 
ported by it per second, or about 50 million tons annually. 

Erosion of the lake shores. — The shores of the Laurentian lakes 
are being eroded at many localities, and the material thus removed de- 
posited, in part, on other portions of the coast so as to add to the land 
area. Some information in this connection has been compiled by Charles 
Crosman,^ but much additional data is required before general conclusions 
of value can be reached. 

The average annual recession of the sea-cliff along the west side of 
Lake Michigan, as determined by Prof. Edward Andrews from a some- 
what extended series of observations, is stated to be about 5 feet ; with a 

1 Analyses of the water of 20 rivers of the United States and Canada may be found in 
Monograph No. XI, U. S. Geological Survey, Table A! 
^ Geological Survey of Canada, 1863, p. 567. 
3 " Chart of the Great Lakes." Published at Milwaukee, Wisconsin. 



RELATION OF LAKES TO CLnLVTIC CONDITIONS. 61 

maximum at certain localities, of 16 feet. In the neighborhood of Cleve- 
land, 'Ohio, the mean recession of a line of prominent sea-cliffs in boulder 
clay, for a period of 40 years, has been about 6 feet per annum. 

Observations at less favorable localities show a similar retreat of 
other portions of the lake shores, bat definite quantitative observations 
have seldom been recorded. Enough is known in a qualitative way, how- 
ever, to show that important changes in the outlines of these lakes are in 
progress. The waste of the shore, resulting in a broadening of the sur- 
faces of the lakes, is compensated in part by the deposition of the material 
removed on adjacent area so as to extend the land lakeward, as, for 
example, at the south end of Lake jNIichigan, where beaches and large 
sand dunes have been formed, and are still encroaching on the lake. 
Observations made by the Avriter at various localities about the shores of 
the lakes, together with the reports of others, show conclusively that the 
process of broadening the lakes by the erosion of their shores is progress- 
ing more rapidly than areas are being reclaimed by deposition, and there- 
fore that they are becoming shallower. 

Commerce and fisheries. — The importance of the Laurentian lakes 
as highways of commerce is too well known and is too extended a subject 
to receive treatment at this time, even if it fell within the scope of the 
present discussion. Some idea of the magnitude of the commerce on 
these inland waters may be had, however, from the reports of the opera- 
tion of the Government locks at Sault St. Marie, which show that 11,557 
vessels passed through them during the year ending June 30, 1892, car- 
rying over 10 million tons of freight. The great importance of the com- 
merce of the Laurentian lakes will be better appreciated, by those who 
are not familiar with it, when it is compared with the traffic of the Suez 
Canal. In 1889, the latest date at which comparative data are at hand, 
nearly three times as many vessels passed through the locks at Sault St. 
Marie as through the Suez Canal, although the latter is open for naviga- 
tion throughout the entire year. The tonnage during the same year was 
7,221,935 at the " Sou," as against 6,783,189 for the Suez Canal. The 
importance of the carrying trade of the Great Lakes is also shown by the 
fact that the tonnage of vessels constructed on them each year for several 
years, has been about equal to that of all the vessels built on the Atlantic, 
Pacific, and Gulf coasts. Still more striking is the fact that the amount 
of goods carried each year on these inland waters, is far in excess of the 
entire clearances of all the seaports of the United States, and several mil- 



62 LAKES OF NORTH AMERICA. 

lion tons in excess of the combined foreign and coastal trade of London 
and Liverpool. 

The demand for still better facilities for inter-lake commnnication has 
led to the constrnction of still larger canals and locks, and now improve- 
ments are nearly completed which will allow vessels drawing 21 feet of 
water to pass from Buffalo to Duluth. It is expected that Avhen this 
improvement is made the trade between Lake Superior and the more 
southern lakes will be doubled in a few years. Far-reaching plans for 
connecting this important commercial industry with ocean highways are 
under consideration, and must find consummation in the near future. 

The fisheries of the Laurentian lakes is another subject of great prac- 
tical importance, as they are the most extensive lake iis'heries in the 
world. The lakes abound in trout, whitefish, and other food fishes, and 
their shores are dotted with fishing villages, in which a hardy population, 
skilled in all that pertains to their calling, are living their humble but 
useful lives, and gaining an experience which well fits them for naval 
service should their aid be called for. The importance of these inland 
fisheries has received tardy recognition in comparison with the similar 
industries of the sea border, but they are a substantial element of national 
wealth and claim the most careful attention and guidance of both state 
and national legislators. The reports of the U. S. Fish Commission show 
that over ten thousand persons are engaged in this industry : that ,the 
capital invested is in excess of four and one-half millions of dollars ; and 
that a hundred million pounds of fish are secured each year, which bring to 
those actually engaged in the work more than two and one-half millions 
of dollars. 

It may be noted as an item of interest in connection with the physical 
history of the Laurentian basin, that in lakes Superior and JNIichigan crus- 
taceans and fishes have been found that are believed to be identical with 
living marine forms. These are thought b}^ some persons to indicate that 
the lakes in which they occur were formerly in open communication with 
the ocean. Considerable evidence, derived from a study of the former 
extent of the lakes, and of the fossils in the sediments of previous 
water-bodies in the same basins, do not seem to confirm this conclusion, 
however, and further study of the habits and means of migration of the 
species referred to, is necessary before their presence in inland waters can 
be satisfactorily accounted for. 

The movements of the waters of the Laurentian lakes and a few facts 
respecting their temperature and their influence on the climate of the 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 63 

adjacent land have already been referred to in preceding chapters. Scarcely 
more than a beginning of their physical study has been made, however^ 
and it is to he hoped that they may soon receive the attention in this 
direction they so well deserve. 

Mountain lakes. — No account of the lakes of North America is com- 
plete that does not include some notice of the thousands of basins amid 
the northern Appalachians, and in the Cordilleras, in which the most 
magnificent scenery of this continent is reflected. These lakes are of all 
sizes, from mere tarns across Avhich one might spring with the aid of an 
alpenstock, to broad plains of blue, many square miles in area, and worthy 
of comparison Avith the most beautiful mountain lakes of other lands. Of 
this attractive class of lakes special attention can only be gi^^en at present 
to tAvo examples AAdiich are destined to be widely knoAvn on account of 
their many charms. I refer to Lake Tahoe, embosomed among the peaks 
of the Sierra NcA^ada, and lying partially in California and partially in 
NcA'ada ; and to a lake of a different character but not less magnificent, 
situated in the Cascade mountains, in the State of Washington, and knoAvn 
as Lake Chelan. 

Lake Tahoe. — This " gem of the Sierra " is situated at an elcA^ation 
of 6200 feet al^oA'e the sea and is enclosed in all directions by rugged, 
forest-covered mountain slopes which rise from two to over four thousand 
feet aboA^e its surface. Its expanse is unbroken by islands and has an 
area of betAveen 192 to 195 square miles. Its diameter from north to 
south is 21.6 miles and from east to AA^est 12 miles. 

On looking doAvn on Lake Tahoe from the surrounding pine-coA^ered 
heights, one l^eholds a vast plain of the most Avonderful blue that can be 
imagined. Near shore, AA'here the bottojn is of AA'hite sand, the Avaters have 
an emerald tint, but are so clear that objects far beneath the surface maA' 
be readily distinguished. Farther lakcAvard, the tints change by insensible 
gradation until the Avater is a deep blue, unrivaled even by the color of tlie 
ocean in its deepest and most remote parts. On calm sunnner days, the 
sky AA'ith its drifting cloud l:)anks and the rugged mountains Avith their 
l)ai'e and usually snow-covered summits, are mirrored in the i)lacid Avaters 
Avith such wonderful distinctness and such accuracy of detail, that one is 
at a loss to tell Avhere the real ends and the duplicate begins. While 
floating on the lake in a boat, the transparency of the Avater gives the sen- 
sation that one is suspended in mid air, as every detail on the bottom, 
fathoms below, is clearlv (hsceniil)le. 



64 LAKES OF KOETH AMERICA. 

Ill experimenting on the transparency of the waters, Professor John 
LeConte fonnd that a white disc 9.5 inches in diameter, Avhen fastened to 
a line and lowered beneath the snrface, Avas clearly visible at a depth of 
108 feet. It is to be remembered that the light reaching the eye in such 
an experiment traverses through water twice the distance to Avhicli the 
disc is submerged, or in the experiment referred to, 216 feet. The only 
instance in this country in which ^^^^aters have been found to be more 
transparent is in the great limestone-water springs of Florida. 

Soundings made in Lake Tahoe by LeConte, as already stated, gave a 
maximum depth of 1645 feet, but a more detailed survey may possibly 
discover still more profound depths. Those measurements show that the 
lake, with the exception of Crater lake, Oregon, is the deepest inland 
water-body in America yet sounded, and exceeds the depth of any of the 
lakes of Switzerland, but is not so deep as lakes Maggiore and Como on 
the south side of the Alps. 

The temperature observations made in Lake Tahoe previously referred 
to, furnish an illustration of the fact that deep lakes, even when situated 
at a hig'h elevation and subject to low winter temperatures, do not freeze. 
The surface waters are cooled in winter and descend, while warmer waters 
from below rise and take their place, thus establishing a circulation, but 
the body of water is so great that its entire mass never becomes cooled 
sufficiently during the comparatively short winters to check the upward 
circulation and allow ice to form. At the greatest depth reached the 
temperature was 39.2° F., which is the temperature of fresh water at its 
maximum density; and from more extended observation in other lakes, 
the water is believed to retain this temperature throughout the year. 

Lake Tahoe is situated at such an altitude that its shores are bleak 
and inhospitable during a number of months each year. For this reason 
it is probable that it will never be selected as a place of continued resi- 
dence by any considerable number of families, but during the summer, 
when the adjacent valleys are parched by desert heat, the air in the lake- 
filled valley is cool and bracing ; it then furnishes a charming retreat for 
the dwellers of the cities of the Pacific coast, as well as for more distant 
wanderers. As a place for summer rest and recreation it is second to 
none of the popular resorts of the United States or Canada. 

The waters of Lake Tahoe overflow through the Truckee caiion and 
form a blight, swift-flowing stream, which finds its way to Pyramid and 
Winnemucca lakes, situated 2400 feet lower, in the desert valleys to the 
north. The waters when starting on their troubled j(")urney are as pure 



KELATION OF LAKES TO CLIMATIC CONDITIONS. 65 

and limpid as the melting snows of mountiiin \'ulle3"s can fnrnisli. Analy- 
ses show that they contain only 0.0750 part per thousand of mineral 
matter in solution, but the lakes into which they flow and of which they 
form almost the sole supply, are alkaline and saline owing to lono- 
concentration. 1 

An example of an isolated drainage system is here furnished, embrac- 
ing the cool summits of lofty mountains where the moisture of the atmos- 
phere is condensed ; a mountain reseryoir where the ^yaters are stored ; a 
swift, clear stream formed by the oyerjflow of the reseryoir ; and the bitter 
lakes where the stream empties and from which there is no escape except 
by eyaporation. Such an attractive field for geographical study should 
not be long neglected. A careful inyestigation of the yarious problems 
here assembled in narrow bounds, would form a thesis of unusual interest. 
Will not some student or some class of students in our uniyersities tell 
the world what the mountains and streams in this fascinatinof reeion are 
doing, explain how the present conditions came into existence, and point 
out the results towards which they are tending? 

Lake Chelan. — Our second example of mountain lakes, selected from 
the large number that shimmer in the sunlight amid the highlands of the 
Far West, lies hidden in the embrace of the eastward-reaching sjDurs of 
the Cascade mountains in the State of Washington, and until recently 
was so remote from the paths ordinaril}^ followed by man, that its very 
name Ayill sound strange to many of ni}- readers. 

Where Columbia riyer crosses the arid region between the Rocky 
mountains and the Cascade range, making a yast sweep about the north- 
ern and western margins of an ancient lava flood, it washes the bases of 
the mountains to the west and receives the tribute of a number of lakes, 
fed by the melting snow on the higher portions of the range. One of 
these lakes, named in honor of Chelan, an Indian chief of consideral)le 
local renown, whose village stands on its shore, empties into the Columbia 
through a deep tortuous gorge of recent origin and sends a swift stream 
of clear, greenish-tinted water about two miles long, to join the great river 
in the adjacent canon. The lake is a narrow, river-like sheet of Avater, 
with gentle windings, extending westward from the Columbia, seventy 
miles into the mountains, and is bordered on either hand by a continuous 
series of rugged peaks that rise from five to over seven thousand feet 
iibove its surface. The deep, narrow, trench-like yaUey. now partially 

1 For analyses of tlie waters of these lakes, see p. 72. 



QQ LAKES OF NORTH AMERICA. 

water-filled, continues beyond the head of the lake for a distance of at 
least twenty-five miles, becoming more and more wild and rugged as it 
nears the heart of the highlands. The total length of this remarkable 
valley is not less than one hundred miles, and its width at the level of the 
lake seldom exceeds four miles. 

The sounding line has shown that Lake Chelan is over eleven hundred 
feet deep, but its full depth remains to be determined. In several sound- 
ings made by the writer in its central and western portions, no bottom 
was reached at the depth indicated. The surface of the lake is but 950 
feet above the sea, so that the bottom of the trough is below sea level. 

Where the clear water of the lake washes tlie precipitous walls enclos- 
ing it there is no beach, and scarcely a trace on the rocks to shoAv that it 
has altered the topography of the shores. The present conditions were 
initiated at such a recent date that, practically, the only changes they have 
produced are at the eastern end of the lake, where it emerges from the 
rocky defile of the mountains and for a short space expands between com- 
paratively low shores of gravel and sand. In this region high terraces 
mark the former level of the water surface. 

How the great gash in the mountain, fully one hundred miles long, 
and now filled for more than a thousand feet in depth by the lake, was 
formed, is not easy to explain. Previous to the birth of the present lake 
the valley was occupied by a large glacier which flowed through it and 
joined another great ice stream in the caiion of the Columbia. The ice 
smoothed the precipices of rock and piled up moraines on the more, gentle 
slopes at the east end of the valley, but that the main depression existed 
before the glacial invasion is evident and is in harmony with the histories 
of many other valleys in the Cordilleran region. The valley has a still 
more ancient history, and in Tertiary, or in part perhaps in pre-Tertiary 
times, Vv^as excavated in the hard granite, now seen in its enclosing walls, 
by the slow wear of streams. It is a stream-cut channel, but where the 
stream rose that did the work, or whence it flowed, remains to be deter- 
mined by a careful study of all the facts bearing on the problem. 

It has been the writer's fortune to pitch his camp on the borders of both 
Lake Tahoe and Lake Chelan. As the scenery of each is conjured up in 
revery, it is difficult to decide which is the more remarkable or which 
should have the first rank among the mountain lakes of America. Each 
lake is surrounded by forest-covered mountains of majestic proportions 
and rich and varied details ; the waters of each lake are clear and deep in 
color, or varied by silvery reflections and iridescent tints where the not. 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 67 

too gentle- mountain Aviuds touch their surfaces ; in each instance the 
scene is fresh and unmarred, and has the charm of remoteness so welcome 
to many who are weary with the ways of men. 

At Tahoe the views are wide and far-reaching. The shagg}- moun- 
tains are picturesque 1}^ grouped abont the central plain of waters and the 
scene is open and, for a mountain stronghold, mild and pleasing. 

At Lake Chelan the scener}^ is wild and rugged. The narrow stream- 
like sheet of water, with gently curving shores, extends far into the 
mountains and cannot be comprehended at a glance. Each view, as one 
ascends the lake, gives suggestions of something still more grand be3'ond. 
Each turn reveals hidden beauties that entice one on and on. The 
bordering mountains become more and more rugged, as we venture 
farther into their embrace. Each ncA^dy discovered peak is higher and 
more imposing than its predecessor ; until at the head of the lake, the 
most lofty summits of the range, usually white with snow, can be seen far 
up the gorge be^'ond where boats can go. The narrow valley bottom 
beyond the lake is filled Avith majestic trees and a rich profusion of lower 
vegetation of almost tropical density ; the dark vine-entangled forest 
seems striving to conceal some mysterious shrine farther Avithin the 
heart of the mountains. A clear, swift stream flows silently beneath the 
deep shade of the broad-leaved sycamores; and from far Avithin the hidden 
recesses of the valley, the echoes of unseen cataracts come faintly to the 
ear. "What Avonders exist in the upper portion of the A^allej^ are not 
knoAvn, as they haA'e been seen b}^ only a fcAv white men and have ncA^er 
been described. 

All of the surroundings of this wonderful lake are so fresh and speak 
so strongl}' of the untamed beauties of Xature in her Avildest moods, that 
a A^sit to the region has the zest and fascination of entering an undis- 
coA^ered country, Avdiere each step takes one farther and farther into the 
unknown. 

The vegetation of the Cascade mountains is far more luxuriant and 
A^aried than the flora of the Sierra Xe\'ada. In eA'^ery nook and corner one 
is sur[)rised and charmed Avith the rank luxuriance of the gracefully 
bending fern's, or the profusion and brilliancy of the flowers. On the 
higher slopes, between the forests and the bare summits of the cloud- 
capped peaks, the angles of the rock are softened by luxuriant mosses and 
lichens, and the gray of the cold granite is brightened by Alpine blossoms. 

Tent life on the shore of either Lake Tahoe or Lake Chelan is delight- 
ful. Each lake has its own peculiar charms, but their influences on the 



68 LAKES OF NORTH AMERICA. 

mind are different. One or the other will be declared the more attractive 
according to the temperament of the person who yields himself to their 
influences. Each is poetic, and will weave a web of golden fancies in the 
mind of its admirer, which will be as nectar to his thoughts when his feet 
tread other and less inspiring paths. 

Owing to the very moderate elevation of Lake Chelan, its climate is 
mild throughout almost the entire year, and is delightful from early spring 
to late autumn. Since the building of the Great Northern railroad, this 
charming lake of the Cascades is quite accessible. The traveler leaving 
the railroad at Wenatchee, may ascend the Columbia by steamer, to Chelan 
Crossing, a distance of about forty miles, and thus see something of the 
great river of the Northwest. From Chelan Crossing, a ride, or prefer- 
ably a walk of two miles, will bring the visitor to Chelan "City" as a 
unique group of several hundred " claim shanties " is termed. The houses 
in this silent city were built simply for the purpose of acquiring some 
sort of a title to the land on which they stand and were never intended 
for habitation. The generous hospitality of the sparse population in this 
frontier town makes up for their lack of numbers. Every visitor who 
comes to see the beauties of the lake and mountains, of which the dwellers 
of the region are justly proud, will be welcomed. 

On the lake there are small steamers, which make regular trips to its 
head, and boats for sailing and fishing. The trout in the lake are abun- 
dant and unusually fine. Mountain goats inhabit the higher mountains, 
and afford sport equal to the chamois chase. Small hotels have been 
built on the shores of the lake for the accommodation of summer tourists, 
fishermen, and hunters. I mention these details for the purpose of assur- 
ing the reader that he will find traveling easy and agreeable, if he wishes 
to verify what has been stated in reference to the attractions of one of the 
wildest and grandest lakes in America.^ 

Only two examples of the mountain lakes of America have been 
referred to, for the reason that the space at command does not permit even 
the mention of the hundreds of charming examples, many of them of 
greater size and in their milder fashion as attractive as those of the Sierra 
Nevada and Cascade mountains, which add variety and beauty to the New 
England States, New York, etc. Extending our survey to Canada, a still 

1 A more complete account of the region about Lake Chelan than can be given at this 
time, may be found in a report on the Upper Columbia River by Lieut. T. W. Symons ; 47th 
Congress, 1st session, Senate Executive Doc. No. 186, Washington, 1882 ; and in a report by 
the author, on a Geological Reconnoissance in Central Washington, U. S. Geol. Surv., 
Bulletin No. 108. 



KELATIOK OF LAKES TO CLIMATIC CONDITIONS. 69 

greater host of inland water bodies of almost every variety imaginable, 
attract the attention and cause our pen to linger ; but here again we can 
only say that they belong to a great class of which types have been briefly 
described. 

Saline Lakes. 

Saline lakes are formed principally in two ways. First, b}" the isola- 
tion of bodies of sea water, as where a rise of the land cuts off an arm 
of the ocean, or sand bars or coral reefs enclose lagoons. Second, by 
the concentration by evaporation of ordinary river waters in enclosed 
basins. The first are of oceanic and the second of terrestrial origin. 

Saline lakes of oceanic origin. — There are no conspicuous exam- 
ples of this class of lakes in North America, although lagoons cut off 
from the ocean by sand bars do occur, especially along the southern 
Atlantic coast. 

A large lake of salt water that was isolated from the ocean by a rise 
of the intervening laud formerly occupied the valley of Lake Champlain, 
but has been freshened and its surface lowered by overflow. 

The type of saline lakes which were formerly arms of the ocean is 
furnished by the Caspian sea, the largest body of inland water known. 
The observations of many travelers have shown that this sea has been 
divided from the ocean by the elevation of the intervening land. The 
climate of southwestern Asia is arid, and over large areas evaporation is 
in excess of precipitation. For this reason the Caspian has contracted its 
borders, in spite of the large contribution of water delivered to it by the 
Volga and other streams. 

There is evidence in the chemical composition of the waters of the 
Caspian, and in the topography of land separating it from the Black sea, 
to indicate that at first it was freshened by overflow, as in the case of 
the ancient lake of Champlain valley, and that its present salinity has 
resulted principally from the concentration of river waters. It may be 
considered, therefore, of oceanic or of terrestrial origin as one chooses. 

The Caspian is 180,000 square miles in area, or nearl}- six times the 
size of Lake Superior. Its maximum depth is in the neighborhood of 
3,000 feet, and exceeds the depth of any other lake known. It is with- 
out outlet. Its waters contain 6.294 parts in a thousand of mineral 
matter in solution, consisting principally of sodium cliloridt' and mag- 
nesium sulphate. The waters of tlie ocean, it will be remembered, con- 



70 LAKES OF NORTH AjNIERICA. 

tain, on an average, 34.4 parts per tliousand, or, in round numbers, 3.5 
per cent. 

One of the most instructive features connected with the Caspian is 
the manner in which it loses its saline constituents by discharging into 
a secondary basin, where the waters are still more highly concentrated. 
On its eastern shore there is a deep bay or gulf known as Karabogaza, 
which is nearly shut off from the main water-body by intervening sand 
bars, and receives its only influx through an opening in the bar about 
140 yards broad and 5 feet deep. The water escapes from Karabogaza 
solely by evaporation, and is replaced by a current from the Caspian 
which has been estimated by Von Baer to carry 350,000 tons of saline 
matter daily from the sea to the gulf. The waters of the gulf have 
reached the point of saturation for common salt, and precipitation is tak- 
ing place. These peculiar conditions are of great interest, not only in 
showing how deposits of salt may accumulate, but also in illustrating 
the manner in which an enclosed lake may deposit a large part of its 
foreign matter without the entire water-body becoming highly concen- 
trated. 

Saline lakes of terrestrial origin. — The existence of lakes of this 
class depends upon a combination of topographic and climatic conditions. 
The basins they occupy may originate in almost any of the various ways 
enumerated in Chapter I. As a rule the lakes of this class in North 
America occupy depressions formed by movements in the earth's crust 
which have cut off large areas from free di^ainage to the sea. Such en- 
closed basins, however, can only continue in regions where the rainfall 
is small, for the reason that if precipitation were in excess of evaporation, 
they would become filled to overfloAving. The most favorable conditions 
for the formation of inland saline lakes are found where high mountains 
discharge their drainage into basins where the climate is arid. A region 
of condensation of atmospheric vapors and a region of concentration by 
evaporation are thus supplied, Avhich supplement each other. 

The saline lakes of arid regions are peculiarly sensitive to climatic 
changes, and undergo many fluctuations. AVhen the mean annual influx 
and the mean annual loss by evaporation are nearly evenly balanced, lakes 
frequently exist only during the rainy season, and disappear entirely dur- 
ing the hotter portions of the year, leaving broad, smooth mud plains. 
Plains of this character are a characteristic feature of the arid region of 
North America, and are known in ]Mexico and in the southwestern part 



Lakes of Nokth America. 



Plate 14. 




SALINE AND ALKALINE LAKES IN THE ARID REGION. 



EELATIOiSr OF LAKES TO CLIMATIC COXDITIOXS. (1 

of the United States as playas. It is convenient to adopt tliis name, 
and call the temporary water-bodies to which playas owe their origin, 
playa lakes. These lakes may be formed by a single shower and disap- 
pear in a few hours, or they may endure for a series of years and only be 
evaporated to dryness during seasons of exceptionally low rainfall or un- 
usually active evaporation. 

When enclosed lakes of arid regions are more permanent, they fluctu- 
ate in volume, and consequently in extent and in densit}^ from season to 
season, and are so sensitive to climatic changes that they show marked 
variations when ordinary weather observations, taken at a limited number 
of localities in their neis'hborhood, fail to indicate analogfous changfes in 
atmospheric conditions. 

The terrestrial saline lakes of North America are confined to the arid 
region of Mexico and the United States, although small pools of alkaline 
water do occur on the great plains in the sub-humid region east of the 
Rocky mountains both in the United States and Canada. The saline 
lakes of the United States are confined almost entirely to Utah and 
Nevada and adjacent portions of the Great Basin. The distribution of 
some of the more important lakes here referred to, is indicated on the 
accompanying map forming Plate 14. The chemical composition of their 
waters is shown in the table on page 72. 

Chemical precipitates. — The deposition of mechanical sediments, as 
clay and sand, in lake basins has already been referred to. This takes 
place in all lakes without special reference to their chemical composition. 
When lake waters become concentrated by evaporation, however, the 
material contributed to them in solution may be precipitated, and 
either mingle with the mechanical sediments or form deposits of 
purely chemical origin. Chemical precipitates, like mechanical sedi- 
ments, may furnish evidence of important changes in a lake's history, 
and are also frequently of great interest on account of their commercial 
value. 

As already seen, enclosed lakes are constantl}^ receiving contributions 
from streams, springs, and rain, but do not overflow, the influx being 
counterbalanced by evaporation. This assures us tliat in the earlier stages 
of their history, at least, the amount of saline matter held in solution must 
increase from year to year and from century to century. This process 
continuing, a time is eventually reached when the waters will be saturated 
with one or more of its saline constituents and preci})itiiti()n l)egin. Waters 



72 



LAKES OF NORTH AMERICA. 



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RELATION OF LAKES TO CLIMATIC CONDITIONS. 73 

holding a number of salts in solution, when slowly evaporated, do not 
deposit them in a homogeneous mass, but in successive layers of varying 
composition. As the order in which different salts are deposited varies 
with the composition of the waters, it is safe to say that in no two lakes 
is the succession of saline deposits formed on evaporation apt to be the 
same. Disregarding for the present the reaction of the various salts upon 
each other, it is evident that in the evaporation of natural waters the 
order in which the contained salts Avill be precipitated is inversely as the 
order of their solubility. For example, a salt which requires a large 
amount of water for its solution, or, in other words, is sparingly soluble, 
will reach its point of saturation and commence to crystallize out as 
evaporation progresses, previous to the deposition of a more soluble salt. 
To illustrate : it has been found that calcium carbonate requires about 
10,000 times its weight of water, saturated with carbon dioxide, for its 
solution; while calcium chloride is deliquescent, and dissolves in about 
its own weight of water. In an enclosed lake to which streams and 
springs are bringing these two salts in equal quantities, and in which 
evaporation equals or exceeds the supply of fresh water, it is evident that 
the calcium carbonate would reach its point of saturation and commence 
to separate long before the waters had become rich in calcium chloride. 
In fact, owing to the deliquescent nature of the chloride, natural evapora- 
tion seldom proceeds far enough to cause its precipitation. The early 
deposition of calcium carbonate, when natural waters are concentrated by 
evaporation, is rendered the more certain for the reason that it is by far 
the most abundant salt found in surface waters. 

The fact that various salts are deposited in a regular succession when 
mineral waters are evaporated, is of great service in separating certain 
ones in a pure state by the method known as fractional crystallization. 
In evaporating the brines of Syracuse, New York, the precipitation of 
ferric oxide and of calcium sulphate, or gypsum, is first secured b}" mod- 
erate concentration ; the brine is then conducted to lower vats and evapo- 
ration continued until the sodium chloride, or common salt, has mostly 
crystallized and fallen to the bottom ; the mother-liquor, rich in magnesium 
and calcium, is then allowed to go to waste. A similar process frequently 
takes place in nature, but the salts precipitated collect in the same basin 
in alternating la^-ers. 

In the Soda lakes near Ragtown, Nevada, a double cai'bonate of sodium 
and calcium, known as the mineral gajdussite, forms on the bottom, owing 
to natural concentration. When the waters are still farther evaporated, 



74 LAKES OF NOETH AMERICA. 

sodium sulphate and sodium carbonate are precipitated previous to the 
crystallization of common salt. 

It has been found on concentrating sea-water that calcium carbonate 
is usually the first constituent to be precipitated. This salt is not always 
found when the waters of the ocean are analyzed, but may usually be 
detected in samples taken near shore. The vast quantity deli\'ered to 
the ocean by rivers is soon eliminated by plants and animals and secreted 
in their tissues. 

The succession of chemical precipitates formed in sea-water has been 
described by M. Dieulafait ^ as follows : 

" First a very weak precipitation occurs of carbonate of lime (calcium 
carbonate), with a trace of strontium, and of hydrated sesquioxide of iron, 
mingled with a slight proportion of manganese. The water then con- 
tinues to evaporate, but remains perfectly limpid, without forming any 
other deposit than the one I have mentioned, till it has lost 80 per cent 
of its original volume. It then begins to leave an abundant precipitate of 
perfectly crystallized sulphate of lime with two equivalents of water or 
gypsum, identical in geometrical form and chemical composition with 
that of the gypsum-beds. This deposit continues until the water has 
lost 8 per cent more of its original volume ; then all iDrecipitation ceases 
till 2 per cent more of the original quantity of water has evaporated 
away. Then a new deposit begins, not of gypsum, but of chloride of 
sodium, or sea salt. . . . The deposition of pure or commercial salt con- 
tinues till the volume of the water has been again reduced by one-half, 
when a precipitation of sulphate of magnesium begins to take place with 
it. This continues, the two salts being deposited in equal quantities, till 
only 3 per cent of the original quantity of water is left. Finally, when 
the water has been concentrated to 2 per cent, carnallite, or the double 
chloride of potassium and magnesium, is deposited. Spontaneous evapo- 
ration cannot go much further. The residual mother-wateir will not dry 
up at the ordinary temperature, even in the hottest regions of the globe ; 
its chief constituent is chloride of magnesium. A body of sea-water 
evaporated naturally will, then, leave a series of deposits in which we 
will find, as we dig down, the foUov/ing minerals in order: deliquescent 
salts, including chiefly chloride of magnesium ; carnallite, or double chlo- 
ride of potassium and magnesium; mixed salts, including chloride of 
sodium and sulphate of magnesia ; sea-salt, mixed with sulphate of mag- 
nesia; pure sea-salt; j^ure gypsum; weak deposits of carbonate of lime 
Avitli sesquioxide of iron, etc." 

1 Popular Science Monthly, October, 1892. 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 75 

In the natural evaporation of water in enclosed basins tlie succession 
will seldom be as regular as described above, for the reason that the process 
is apt to be interrupted by the addition of fresh supplies of water, and the 
succession begun anew, or else chemical changes initiated which will vary 
the results. In this connection it is to be noted also that changes of tem- 
perature, as from summer to winter, may modify the succession of salts 
deposited. 

The separation of sodium sulphate, potassium chloride, and common 
salt from the mother liquor derived from the concentration of sea-water, 
by alternate evaporation and cooling, is the principle of Balard's well- 
known process largely used for obtaining salt from sea-water in the south 
of Europe. In Mesel's modification of this process, a low temperature is 
obtained artificially. When sea- water is concentrated until its specific 
gravity is 1.21 (28° of Beaume's hydrometer) it deposits about four-fifths 
of the common salt it originall}^ contained ; after adding 10 per cent of 
sea-water to the mother liquor remaining, it is passed through a refriger- 
ating machine and its temperature lowered to — 18° C. The low tempera- 
ture causes double decomposition to take place between the magnesium 
sulphate and the sodium chloride, sodium sulphate being deposited and 
the magnesium chloride remaining in solution. ^ 

A process similar to that just described occurs in nature, as is shown 
by the precipitation of large quantities of sodium sulphate from the waters 
of Great Salt lake, during cold weather. This anticipation of Balard's 
process is noticed in advance in connection with other features of Great 
Salt lake. 

The correspondence between the succession of salts formed by the 
evaporation of sea-water, and the succession found in many saline deposits 
deeply buried in the earth's crust, is of great interest and no doubt 
explains the genesis of some natural accumulations of this character. It 
is not always necessary, however, in seeking an explanation of the origin 
of beds of common salt, gypsum, etc., found in lenticular masses among 
stratified rocks, to assume that they were precipitated from isolated bodies 
of sea-water. On the contrary, the study of saline lakes has shown that 
similar deposits may result from the long concentration of ordinary 
river waters. So far as we are at present concerned, however, the 
process in either case is tlie same, since the waters of the ocean itself 
owe their salinity in a great degree to the concentration of the waters 
of streams. 

1 Keport of .Juries : Iiiternathjiial Exliiljition, 1862, Class II, pp. 48-54. 



76 LAKES OF NORTH AMERICA. 

Knowing the succession in wliicli various salts are eliminated when 
waters are concentrated by evaporation, it becomes possible to determine 
in some instances, from the succession of salts discovered in a desiccated 
lake basin, what changes occurred in the life of the lake from which they 
were precipitated. In the case of Lake Lahontan, described in advance, 
this method has led to interesting conclusions. In a similar way, the 
t3hemical composition of a lake enables one to draw important inferences 
in reference to its past history. A lake in which the rarer elements found 
in tributary streams are abundant, must have undergone a long period of 
concentration, and formed deposits of the more common and less readily 
soluble salts. If a lake occupying an inclosed basin which has never 
overflowed, contains but a small percentage of the salts most common in 
the inflowing streams, it is evident that there must be some process by 
which such salts may be eliminated without being flooded out. Search 
should then be made for this new principle. 

When lake waters are concentrated the first precipitates formed, as 
already seen, are ferric oxide and calcium carbonate. These substances are 
retained in solution mainly by reason of the presence of carbon dioxide, 
carbonic acid, in the water. As evaporation progresses and also when the 
waters are agitated, as in the breaking of waves on shore, the carbon 
dioxide escapes and the iron and lime previously held in solution are 
precipitated. The iron while in solution is in chemical combination with 
the carbon dioxide, forming ferric carbonate, when it loses its carbonic 
acid it is precipitated as ferric oxide. The lime in solution is believed 
to be in the form of the bicarbonate, and on losing carbon dioxide is pre- 
cipitated as the carbonate. 

It is a fact of geological interest that iron and lime held in solution 
may also be precipitated on account of the withdrawal of carbon dioxide 
through the agency of plant life. Low forms of vegeta^tion, known as 
algae, thrive in the waters of both fresh and saline lakes and even in hot 
springs where the temperature approximates to that of boiling water. 
Through the vital action of this vegetation carbon dioxide is removed 
from water in much the same manner that higher forms of plant life 
eliminate it from the atmosphere. Carbon is assimilated and oxygen 
liberated. Iron on parting with its carbon dioxide unites with the liber- 
ated oxygen and is precipitated as ferric oxide. 

It has recently been shown that large deposits of both calcareous tufa 
and silicious sinter are deposited through the agency of fresh water algae 
from the waters of hot springs in the Yellowstone Park. The silicia 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 77 

in such instances seems to be secreted by the plants as a part of their 
vital function, but the process is not well understood. ^ 

The origin of oolitic sand, consisting of little spheres formed of 
concentric coats of calcium carbonate, along the shores of Great Salt lake, 
has been referred to an analogous process. ^ 

Coral-like growths of calcareous tufa in some of the strongly alkaline 
lakes of the Great Basin are also thought to owe their origin to the 
agency of low forms of plant life.^ 

An important feature in this function of sub-aqueous plants, is that 
calcium carbonate may be precipitated from waters that are far below the 
point of saturation. In some instances precipitation is known to occur in 
this manner from water in which chemical tests fail to reveal more than a 
trace of calcium. 

Ferric oxide is not kno^vn to be an important deposit in any of the 
lakes of North America, although found in abundance in many swamps. 
In Sweden, however, its precipitation from the water of fresh lakes is so 
abundant that it is of commercial value. The iron is carried into the 
lakes by streams, as a carbonate, and is precipitated on account of the loss 
of carbon dioxide, in part at least, through the agency of low forms of 
vegetative life. In some instances diatoms are thought to play an im- 
portant part in secreting the iron. 

With this brief sketch of the manner in which precipitates may be 
formed in lakes, let us turn to actual cases where the process is in 
operation. Of the considerable number of saline lakes of North America 
that have been studied, two are here selected as types. These are Great 
Salt lake, Utah, and Mono lake, California. 

Great Salt lake, Utah. — This celebrated sea is situated in the eastern 
jDortion of the Great Basin near the west base of the Wasatch mountains. 
Its hydrographic basin has an area of 54,000 square miles, and is divided 
iiito two strongly contrasted portions. The eastern part is mountainous 
and contains peaks 12,000 feet in height above the sea, or 8000 feet above 
the lake. The western portion is composed of desert valleys but little 
elevated above the lake surface, and separated by narrow, abrupt, desert 
ranges rising from one to two thousand feet or more above adjacent valleys. 

1 W. H. Weed. " The Formation of Travertine and Silicious Sinter by the Vegetation 
of Hot Springs," 9th Annual Report, U. S. Geological Survey, 1887-88, pp. 613-676. 

2 A. Rothplitz. "On the Formation of Oolite," American fteologist, vol. 10, pp. 279-282. 

3 I. C. Kussell. "A Reconnoissance in Central Washington," Bulletin No. 108, U. S. 
Geological Survey, pp. 9'4-9o. 



78 LAKES OF NOETH AMERICA. 

The elevation of the lake's surface varies somewhat during different 
years and from season to season, owing to climatic changes, and to the 
fact that the flow of the streams supplying it is interfered with for pur- 
poses of irrigation. Surveys made May 16, 1883, gave a surface level of 
4218 feet above the sea. 

Its area is also changeable. On a map made from surveys under the 
direction of Lieut. Stansbury, in 1850, it is represented as having an area 
of about 1750 square miles. A second map, made in connection with the 
Fortieth Parallel survey, in charge of Clarence King, in 1869, shows an 
area of 2170 square miles ; the increase in 19 years being 420 square 
miles, or 24 per cent. Its outlines when these surveys were made are 
shown in Plate 15. 

At its highest observed stage in 1869, it had a maximum depth of 49 
feet, and an average depth of approximately 19 feet. In 1850, the maxi- 
mum depth was 36 feet, and the average about 13 feet. Since 1875, 
careful records of the fluctuations of level have been made and both 
annual and secular changes noted.^ The annual high-water stage occurs 
in June, and is due to the melting of the snow on the Wasatch and 
Uintah mountains. The fluctuations embracing a series of years have 
not been found to be regular in their periods and are not coincident with 
observed climatic changes. 

The shores of Great Salt lake are low except where a mountain uplift 
projects into it from the north, forming a rocky promontory, and for a 
short distance on its south shore where it touches the northern end of the 
Oquirrh mountains. Its surface is broken by several islands, of which 
two are short mountain ranges of the type so characteristic of the Great 
Basin. These rise more than a thousand feet above its surface and are 
rugged and precipitous. They stand like Nilometers in the saline waters, 
and on their sides are many horizontal lines marking former levels of the 
lake's surface. The highest of these scorings is about 1000 feet above 
the present water surface. 

The scenery about this great lake of the Mormon land and in the encir- 
cling mountains is unusually fine, in spite of the aridity and the generally 
scant vegetation of the region. The sensation of great breadth that the 
lake inspires, together with the picturesque islands diversifying its sur- 
face, and the utter desolation of its shores, give it a hold on the fancy, and 
wakens one's sense of the artistically beautiful in a way that is unrivaled 

1 The records of these changes up to 1890, together with a discussion of their significance, 
is given by G. K. Gilbert, in Monograph No. 1, U. S. Geological Survey. 



L.UvES OF XOETH AMEEICA. 



Plate 15. 




GREAT SALT LAKE, UTAH. (.After Gilbert) 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 79 

by any other lake of the Arid region. The unusually clear air of Utah, 
especially after the winter rains, renders distant mountains remarkably 
sharp and distinct, particularly Avhen the sun is low in the sky and a 
strong sidelight brings the sharp serrate crests into bold relief and reveals 
a richness of sculpturing that was before unseen. At such time the colors 
on the broad deserts, and amid the purple hills and mountains, are more 
wonderful than artists have ever painted, and exceed anything of the 
kind witnessed by the dweller of regions where the atmosphere is moist 
and the native tints of the rock concealed by vegetation. The hills 
of New England when arrayed in all the gorgeous panoply of autumnal 
foliage are not more striking than the desert ranges of Utah when 
ablaze with the reflected glories of the sunset sky. The rich, native 
colors of the naked rocks are then kindled into glowing fires, and each 
cafion and rocky gorge is filled with liquid purple, beside which even the 
Imperial dyes would be dull and lusterless. At such times the glories of 
the hills are mirrored in the dense water of the lake ; their duplicate 
forms appearing in sharp relief on the paler tints of the reflected sky. 
As the sun sinks behind the far-off mountains, range after range fades 
through innumerable shades of purple and violet until only their highest 
battlements catch the fading glory. The lingering twilight brings softer 
and more mysterious beauties. Ranges and peaks that were concealed by 
the glare of the noon-day sun, start into life. Forms that were before 
unnoticed, people the distant plain, like a shadowy encampment. At last 
each remote mountain crest appears as a delicate silhouette, in which all 
details are lost, drawn in the softest of violet tints on the fading yellow 
of the sky. 

To one who only beholds the desert land bordering Great Salt lake in 
the full glare of the unclouded summer sun, when the peculiar desert 
haze shrouds the landscape and the strange mirage distorts the outline of 
the hills, the scenery will no doubt be uninteresting and perhaps even 
repellent. But let him wait until the cool breath from the mountains 
steals out on the plain and the light becomes less intense, and a transfor- 
mation will be witnessed that will fill his heart with wonder. 

The saline and alkaline shores of Great Salt lake are either naked 
mud plains, frequently white with drifting salts, or scantily clothed witli 
desert shrubs. The absence of conspicuous flowers is frequently relieved 
by broad areas covered with a peculiar plant, known as Salicornia^ which 
flourishes by the side of this Dead Sea of the West, where all other vege- 
tation perishes. The Salicornia grows in fleshy stems, without leaves, 



80 LAKES OP NORTH AMERICA. 

and looks not unlike brandling coral. It is of many shades of red, pink, 
and yellow, thus still further increasing its resemblance to groves of living- 
coral. The white, alkaline desert is frequently tinted by this strange 
plant until it glows like a field of Alpine flowers. There are many other 
interesting features to be noted by the visitor to the great desert-lake of 
Utah, but its physical and chemical history claims our attention at this 
time rather than its artistic setting. 

The streams flowing to the lake rise in the high mountains to the east 
and are clear and limpid, and of such purity that only chemical tests 
reveal the presence of the mineral matter they have dissolved from the 
rocks and soils. Several of these streams are truly rivers in volume, as 
well as in name, and send a never-ceasing flood to the lake. Their com- 
bined volumes average throughout the year about 10,000 cubic feet per 
second.! 

There are a number of fissure springs about the lake, or rising beneath 
its surface. In some instances these are hot and contain more saline 
matter in solution than is usually found in surface streams. These con- 
tribute a considerable quantity of the saline matter found in the waters of 
the lake, but it is believed that the amount thus derived is less than that 
furnished by streams from the mountains. This conclusion rests on 
incomplete data, however, as neither the volume nor the composition of all 
the springs is known. None of the springs supplying the lake, with a 
single known exception, of small volumes, are markedly saline. The salts 
they contain are acquired largely during the upward passage of the water 
through the sediment of former lakes and their influence on the chemistry 
of the present lake is more important than in the case of any other lake in 
the same region. It is safe to conclude, however, that the combined 
volumes of the streams and springs now tributary to the lake, if not con- 
centrated by evaporation, would form a water body in which no trace of 
saline matter would be apparent to the taste. 

Analyses of the waters of Bear river, of Utah lake, from which the 
Jordan flows, and of City creek, one of the numerous streams from 
the west slope of the Wasatch mountains, give an average of about 
0.2446 part per thousand of mineral matter in solution. This may be 
taken as the average composition of the surface stream flowing to the 
lake. As will be noticed on referring to the average composition of 
normal rivers previously given, the mineral matter in these streams is 
nearly double the amount carried in the same volume of water by streams 

1 G. K. Gilbert. "Lands of the Arid Eegion," Washington, 1879, p. 72. 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 



81 



in more humid regions. This is due, in a measure, to the active evapora- 
tion that takes place from them and from the lakes on their courses. 

The waters of Great Salt lake have been analyzed at six different 
times. The results of these several analyses are widely at variance on 
account of fluctuations in the volume of the lake. The dates at which the 
various samples analyzed were collected and the total solids found in 1000 
parts of water are here given : ^ 

Date . . . 1850 summer 1869 Aug. 1873 Dec. 1885 Aug. 1889 Aug. 1892 2 
Specific gravity 1.170 1.111 1.102 1.122 1.157 1.156 



Parts in 1000 224.2 



148.2 



136.7 



16^ 



195.5 



205.1 



Since the accompanying table of analysis of lake Avaters was compiled, 
my attention has been directed to the analysis given below, which in 
several ways is the most complete and satisfactory that has been pub- 
lished. 



Analysis of a sample of the "Water of Great Salt Lake. Collected 

August 9, 1892.2 

By E. Waller. 
[Expressed In Grams in a Liter. Specific Gravity, 1.156.] 



Elemeitts ajsb Radicals. 


Probable Combination. 


Xa 75.825 

K 3.925 

Li 0.021 

Mg 4.844 

Ca 2.424 

Cl . ■ 128.278 

SOg 12.522 

in sulphates 2.494 

FeoOg and AUOg 0.004 

Si62 . . .' 0.018 

BO2O3 Trace 

Br 3 Faint trace 


NaCl 192.860 

K2SO4 8.756 

LigSO^ 0.166 

MgCU 15.044 

MgSO^ 5.216 

CaSO^ 8.240 

FeoOg and AI2O3 0.004 

Si62 0.018 

Surplus SO3 0.051 


Total 230.355 

Total solids by evaporation . 238.12 
^' [duplicate] . . . 237.925 



The average composition of the combined spring and stream Avaters 
tributary to the lake cannot be stated with accuracy, but judging from 

^ A compilation of various analyses of the water of Great Salt Lake and a discussion con- 
cerning them, is given by G. K. Gilbert, Monogi-aph No. 1, U. S. Geological Survey. 

2 School of Mines [Columbia College] Quarterly, vnl. 14. 1802, p. 58. 

3 A later determinatinn showed almut 0.01 yrain of I'.r. in a litur. 



82 LAKES OF NORTH AMEBIC A. 

such observations as bear on the question, it seems safe to assume that 
their mingled waters would contain less than double the percentage of 
saline matter found in the surface streams. The assumption that the 
combined spring and stream waters would contain about 0.3 part in a 
thousand, or three one-hundi-edths of one per cent of total solids in solu- 
tion, seems as close an approximation as can now be reached. 

The waters of the lake during recent low stages have become nearly 
saturated with sodium chloride and sodium sulphate, and under certain 
conditions these salts are precipitated. The point of saturation for 
calcium carbonate is passed, and this salt is precipitated probably as 
rapidly as it is received. The waters are not rich in the compounds of 
bromine, boron, lithium, and iodine, which frequently occur in " mother- 
liquors," remaining when the more common salts have been eliminated by 
long concentration, and hence indicating the old age of a lake containing 
them. The recent analysis by Waller, however, shows these rarer elements 
to be present in somewhat larger quantities than was previously supposed. 

The length of time that would be 'required to charge Great Salt lake 
with the common salt it contains, under the present conditions, is estimated 
by Mr. Gilbert at about 25,000 years. 

The quantity of sodium chloride, or common salt, held in the water 
of the lake is estimated at 400 million tons, and the sodium sulphate at 
30 million tons. These figures indicate the commercial importance of 
this great reservoir of brine. The separation of the common salt has 
already led to a considerable industry, as from 20 to 40 thousand tons 
have been gathered yearly for a considerable period. The most extended 
and best conducted of these operations are carried on by the Inland Salt 
Company at the southern end of the lake. Evaporating vats covering- 
more than one thousand acres have been constructed, and are supplied by 
pumps which deliver 14,000 gallons of lake water per minute. Pumping 
is continued through May, June and July, and the salt is ready for gather- 
ing in August. During midsummer the amount of water evaporated is 
8,400,000 gallons daily. The yield of salt is at the rate of 150 tons per 
inch of water per acre. An average season's yield is a layer of salt about 
seven inches thick, which would be precipitated from forty-nine inches of 
water. The facilities for this industry may be judged by the fact that 
coarse salt packed on cars ready for shipping, is sold at the Avorks for one 
dollar per ton. The mother-liquor is allowed to go to waste, but it is to 
be expected that sodium sulphate and other salts contained in it will be 
utilized in the near future. 



EELATIOX OF LAKES TO CLIMATIC CONDITIONS. 83 

Along the margin of Great Salt lake, where the water is only a few 
inches deep, it becomes so concentrated by evaporation that common salt 
crystallizes and forms a brilliant white layer on the bottom. In fording 
an arm of the lake about a mile broad, in order to reach Stansbury island, 
the writer, in 1880, found a crust of salt forming a glistening pavement 
strong enough to support a horse and rider, but occasionally it would 
give way and lead to uncomfortable flounderings in the black mud 
beneath. 

The solubility of sodium sulphate is controlled largely by tempera- 
ture. In Great Salt lake in summer it is all dissolved and the waters are 
clear, but as cold weather approaches it separates and renders the Avaters 
opalescent and somewhat milky in color. In the depth of winter, when 
the temperature falls below zero of the Fahrenheit scale, as it does at 
times for days together, this salt separates in great abundance and is 
thrown ashore by the waves in hundreds of tons, forming a slush-like 
mass on the beach looking like soft snow. On such occasions it can be 
gathered in practically unlimited quantities, but is soon re-dissolved when 
the temperature rises. 

The brine of the lake is so concentrated that fish cannot live in it, but 
it furnishes a congenial home for small crustaceans known as brine shrimps 
[Artemia) and for the larvae of dipterous insects. These are abundant 
at certain seasons, but not in such vast numbers as in some of the more 
alkaline lakes on the west side of the Great Basin. It has been stated 
that the vast numbers of crustaceans and of larvae in these waters are due 
to the fact that there are no fishes or other animals in the lakes that 
could prey upon them ; aquatic birds, however, feed upon them in great 
numbers, but still they swarm in countless myriads. Their food seems 
to be minute algae of which several species have been described. 

As shown by the analysis given above, the principal salt in Great Salt 
Lake is sodium cldoride. In the second example of the saline lakes 
described below the characteristic ingredients are sodium carbonate and 
sodium sulphate. Great Salt lake may be said to be a salt lake in 
distinction from a number of water bodies situated especially on the 
west side of the Great Basin, which may with propriety be designated 
as alkaline lakes. 

Mono lake, California. — This lake, selected as the tj'pe of a series 
of strongly alkaline water-bodies in the desert basins of the Arid region, 
is situated in south-eastern Califcn-nia, within a few miles of the Nevada 



84 LAKES OF NORTH AMEEICA. 

bounclaiy. It lies at the immediate eastern base of the Sierra Nevada, 
from which it receives practically all of its water supply, and occupies 
one of the minor basins composing the great area of interior drainagfi 
known as the Great Basin. Its position on the west side of the Great 
Basin and at the base of the great fault scarp forming the precipitous 
eastern slope of the Sierra Nevada, is similar to the situation of Great 
Salt Lake on the east side of the same broad desert area, and at the west 
base of the magnificent fault scarp forming the abrupt western face of the 
Wasatch range. Mono lake, like many other enclosed water bodies of 
the Arid region, is of ancient lineage, as is shown by numerous beach 
lines, carved by former water bodies, on the inner slopes of this valley. 
The highest of these lines is from 670 to 680 feet above the present water 
surface. 

The hydrographic basin of Mono lake has an area of nearly 7000 
square miles, and, as in the case of the region draining to Great Salt lake, 
is divided into two strongly contrasted portions. The southwestern part 
is mountainous and rugged, and bristles with serrate peaks that rise over 
six thousand feet above the lake's surface. On the mountains the snow- 
fall is abundant, and several small glaciers exist in the higher valleys. 
The eastern portion of the drainage basin is comparatively low, and is 
arid and desert-like in character. Little rain falls on this portion of the 
basin, and there are no perennial streams. Only occasionally is there 
sufficient precipitation to produce a surface drainage, and normally the 
rain water and the water produced from the melting of the light Avinter 
snows, is absorbed at once by the thirsty soil or returned to the atmosphere 
by evaporation. 

To gain a comprehensive idea of the geography of the interesting 
region about Mono lake, one should climb some commanding summit on 
the High Sierras, on its southwestern border, and study the magnificent 
panorama spread out at his feet. Let the reader come with me to the 
summit of Mt. Dana, named in honor of the venerable J. D. Dana, one 
of the most prominent peaks overlooking Mono lake, and I will endeavor 
to point out some of the more interesting features of the land we are 
studying. 

The summit we have reached is nearly 13,000 feet above the sea. The 
only neighboring mountains exceeding it in altitude are Mt. Lyell and 
Mt. Ritter, which rise with dazzling whiteness against the southern skj. 
From our station the entire Mono basin is in view, and much of its his- 
tory can be read as from a printed page. We are standing on one of the 



o 




RELATION OF LAKES TO CLIMATIC CONDITIONS. 85 

highest points on the rim of a sharply defined hydrographic basin. The 
di-ainage from all directions tends towards the center and forms a lake 
from which the waters escape only hj evaporation. We can trace nearly 
the entire boundarj^ line of the basin, for the reason that the slopes are so 
plainly marked and the crest lines so sharply drawn, that there is no doubt 
as to the direction that surface water would take. The courses of the 
swift, bright stream descending the mountain can be followed from their 
sources in melting snow-fields, down through deep caiions to where they 
enter the lake. On the desert side of the basin, however, there are no 
streams, and but indefinite traces of the dry beds of former Avater-courses. 
There is no notch in the rim of. the basin to suggest a former outlet. The 
only possible point of discharge for the waters when the ancient beaches 
scoring the inner slopes of the valley were formed, is far to the north, and 
concealed from view. Apparently at our feet, but in reality a mile in 
vertical descent below, lies the lake, a silent and motionless plain of blue. 
Should tlie wind chance to be strong in the A'allej^ ho^^-ever, its surface 
Avould be ruffled, the flash of breaking waves would reach the e^-e, and 
long lines of froth Avould streak its surface. At such times abroad fringe 
of snowy foam, produced by the churning of the alkaline waters, encircles 
the shores and renders their outlines unusually distinct. Apparently 
floating on the surface of the lake, there are two conspicuous islands, the 
forms of which show that they are of volcanic origin. That these craters 
were built since the encircling Avaters fell below their level, is shown 
by their unbroken contours and by the absence of terraces on their outer 
slopes. 

Beyond the lake the brown and barren land seems low and feature- 
less, because of the elevation of our point of view. We can see far be- 
yond the limits of the drainage basin, in which Ave are now specially 
interested, and distinguish many of the desert ranges of Nevada rising- 
above the purple haze enshrouding their bases and obscuring the lifeless 
lands betAveen. The highest of these distant summits, Avhich appears like 
a spectral mountain floating in the sky, is even higher than the peak 
on Avhich we stand, but its naked sides are scorched to a cinder-hke 
redness by the desert heat, and no sih'^ery stream can be detected in 
the wild gorges scoring its flanks. Its summit is seldom cloud-eaj)j)ed. 
and only in the depth of Avinter is its ruggedness concealed by a 
mantle of snow. 

To the rig-ht of the lake is a long range of craters built of frao"ments 
of volcanic rock throAvn out during many Aaolent eruptions, and now 



86 LAKES OF NORTH AMERICA. 

forming conical piles witli gracefully sweeping outlines. Several of these 
now silent volcanoes rival Vesuvius in height and beauty, but from our 
elevated stations we can look down upon the depressions in their summits, 
and the entire range, although two miles in length, with peaks rising 
three thousand feet above the lake that bathes its feet, is but a minor 
feature in the extended landscape. ) 

Northwest and southeast from the summit of Mt. Dana the crest line 
of the Sierras is marked by mountain after mountain as far as the eye can 
reach. Turning south Ave have in view a fine example, though not the 
very finest, of the Avild and rugged High Sierras. At the Avestern base of 
the Mount Dana there is a deep, picturesque valley, dotted Avith lakes 
and traced by gleaming streams. Like nearly all of the more pronounced 
depressions in the High Sierras, this valley OAves its origin principally to 
stream erosion, and is a relic of an ancient drainage system, but has 
been enlarged and its minor features modified by ice abrasion. At one 
time it Avas occupied by a glacier, Avhich formed a part of a great system of 
ice fields that covered all of the High Sierras and sent many ice streams 
both to the east and Avest, through precipitous gorges to the valleys 
below. 

The rocks forming the nearer slopes as one looks toAvard the more 
rugged portion of the range are of varied character and rich in color ; but 
farther Avithin the heart of the mountains the monotonous gray coloring 
of granite is but partially concealed by the scanty forests in the canons 
and valleys, or by the mosses and lichens on the higher summits. Near 
at hand, but across a deep intervening valley, rises Mt. Conness, bare, 
rugged, and grand. TavcIvc miles to the south, across a fragment of 
deeply eroded table-land, named the Kuna crest, are the spire-like peaks 
of Mts. Lyell and Ritter. Throughout the year their summits are white 
Avith snoAV, and small glaciers can be distinguished in the folds of their 
rugged sides. Returning from this Adsion of Avild magnificence, the eye 
rests upon a scene humbler in its charms but not less pleasing. BetAveen 
the naked crags forming the summit from Avhich Ave haA^e gained our com- 
manding view, and the highest limit of the pines, all tAvisted and deformed 
from unequal struggles Avith wind and drifting snow, there is a belt of 
rugged precipices and Aveather-beaten rocks that at certain seasons are 
bright Avith lichens and fringed Avith the purple and gold of alpine blos- 
soms. These charming decorations on the mountain's broAv flourish Avith 
rank luxuriance in every cranny and cleft, and not infrequently are in 
such rich profusion that an entire summit-peak is tinted by them as 



RELATION OF LAKES TO CLIMATIC CONDITIONS. 87 

with a twilight glow. In these elevated regions ]May-clay is a festival of 
late summer, but it brings with it a multitude of charms that are unknown 
to dwellers in the world below. 

The mountains hold out innumerable charms to detain us, but we 
must descend in our fireside journey, and learn more of the strange lake, 
the setting of which was revealed from our station on the mountain top. 
Our downward journey is through a deep gorge witli nearly vertical walls ; 
in its bottom a swift, clear stream plunges from ledge to ledge, and rushes 
through rocky chasms with a roar that never allows the echoes of the 
cliffs a moment's pause. This pure stream of cold, delicious water reveals 
the character of many creeks and rivulets that are rushing down the 
mountain side to the ever-thirsty valley below. 

A few springs add their waters to the supply from the mountains, 
but none of them are saline, and their united volume is far less than the 
volume of any one of half-a-dozen of the mountain torrents pouring into 
Mono lake. The present density of the lake water is the result of the 
long concentration by evaporation of the supply from, the mountains. 

The area of Mono lake in the summer of 1883, was 87 square miles, 
but varies with the seasons and also from year to year. As may be 
learned from the accompanying map, its north and south axis measures 
11, and its east and west axis 14 miles. Its surface is broken by two 
volcanic islands and by numerous crags, some of Avhich are remnants of 
islands now nearly eroded away, while others are formed of calcareous 
deposits precipitated about submerged springs. The soundings given 
on the map, show that its maximum depth is 152 feet, and the mean 
depth about 61 or 62 feet. Its elevation above the sea, when surveyed 
in 1885, was 6380 feet. 

In Pleistocene times, when great glaciers descended from the High 
Sierras and were prolonged several miles into the valley, the ratio between 
inflow and evaporation was changed, and the lake rose, but never suffi- 
ciently to discover an outlet. During the time of its greatest expansion, 
it had an area of 316 square miles, and formed an unbroken water surface 
28 miles long from north to south, and 18 miles broad. Its maximum 
depth was then over 800 feet. 

The facts of greatest interest in connection with Mono lake are to be 
found in its chemical history. As shown in the analysis of its waters 
given on page 72, it is strongly impregnated with sodium and with car- 
bonic and sulphuric acids. The most probable combination of these and 
other substances present in the waters is given bel()\7 : 



LAKES OF NOETH AMERICA. 



Hypothetical Composition^ of the Water of Moxo Lake. 
By T. M. Chatard.i 



CONSTITUEXTS. 


Grams ix a Liter. 


Pee cent of Totajl 

Solids. 


Silica, SiOg 


0.0700 


0.13 


Aluminum and ferric oxide (AlgFeg) O3 


0.0030 


0.005 


Calcium carbonate, CaCOg . 


0.0050 


0.09 


Magnesium carbonate, MgCOg 




0.1928 


0.36 


Sodium borate, Na^B^O^ 




0.2071 


0.39 


Potassium chloride, KCl 




1.8365 


3.44 


Sodium chloride, NaCl 




18.5033 


34.60 


Sodium sulphate, NajSO^ 




9.8690 ^ 


18.45 


Sodium carbonate, ISTagCOg . 




18.35.56 


34.33 


Sodium bicarbonate, NaHCOg 




4.3856 


8.20 


[S]3ecific gravity, 1.045.] 




53.4729 


100.00 



As may be seen in the above table, sodium carbonate and bicarbonate 
form 42.53 per cent of tlie total salts held in solution. The total quan- 
tity of these salts contained in the lake is estimated at 92 million tons, 
the total saline content being 245 million tons. 

Owing to the cost of transportation and the high price of labor, this 
brine is not now utilized, but it forms a reservoir that may be drawn upon 
in the future. The waters of Owens lake, situated a hundred miles south 
of Mono lake, where the commercial conditions are somewhat more favor- 
able, is already the basis of a large soda industry. Two small lakes on 
the Carson desert, known as the Ragtown ponds, or Soda lakes, also 
furnish large quantities of sodium carbonate and bicarbonate. There are 
also several other lakes of the same general character in the Avestern part 
of the Great Basin which have not yet been found of economic impor- 
tance. One of the most promising of these, from a commercial point of 
view, is Soap lake, in the State of Washington. 

The great abundance of sodium carbonate and bicarbonate in Owens, 
Mono, and other lakes on the west side of the Great Basin, in contrast 
with the amount of these salts in the brine of Great Salt lake and of other 
similar water bodies on the east side of the Great Basin, is due mainly to 
differences in the character of the rocks of the two regions. The moun- 
tains on the west are largely formed of volcanic rocks, and yield alkaline 
1 Amer. Jour. ScL, 3d Ser., vol. 36, 1888, p. 149. 



EELATIOIS^ OF LAKES TO CLIMATIC CONDITIONS. 89 

salts to the waters flowing over them or percolating through their inter- 
stices ; while the rocks of the eastern area are largely sedimentary in 
origin, and supply sodium chloride in excess of sodium carbonate. 

The chemical histor}' of the lakes of the Arid region is not only an 
interesting and attractive study, but one of great economic importance, 
as they hold an almost unlimited supply of common salt, and of sodium 
carbonate and bicarbonate, sodium sulphate, and other salts in less abun- 
dance. This supply is still farther augmented by the deposits of former 
lakes now evaporated to dryness. The salts precipitated from these ex- 
tinct lakes, in some instances, Avhiten the surfaces of desert valle3"s, but 
more frequently they are buried beneath or absorbed in the clays forming 
the smooth plains left by the evaporation of playa lakes. 

The importance of the lakes of the Arid region to those interested in 
salt and alkali industries is so great that the table on page 72 has been 
inserted to show the comparative values of the brines thus far analyzed. 
More detailed information in this connection may be found in the publi- 
cations cited below.i 

1 G. K. Gilbert, "Lake Bonneville," U. S. Geol. Surv., Monograph No. 1. — I. C. Eussell, 
"Lake Laliontan," U. S. Geol. Surv., Monograph No. 11. — I. C. Russell, "Lake Mono," 
U. S. Geol. Surv., 8th Ann. Rep., 1886-87, pp. 287-299. —I. C. Russell, " Reconnoissance in 
Washington," U. S. Geol. Surv., Bulletin No. 108. —T. M. Chatard, "Natural Soda," U. S. 
Geol. Surv., Bulletin No. 60. — T. M. Chatard, "Analyses of the Water of Some American 
Alkaline Lakes," Am. Jour. Sci., 3d Ses., vol. 36, 1888, pp. 146-150. —T. M. Chatard, 
"Urano," Am. Jour. Sci., 3d Ses., vol. 38, 1889, pp. 59-66. —J. E. Talmage, "The waters 
of Great Salt Lake," Science, vol. 14, 1889, pp. 444-446. —E. Waller, "Analysis of the 
Water of Great Salt Lake," School of Mmes [Columbia College] Quarterly, vol. 14, 1892, 
pp. 56-61. 



CHAPTER V. 

THE LIFE HISTORIES OF LAKES. 

Lakes, like many other features of the earth's surface, as stated 
in our introductory chapter, have their periods of growth, adolescence, 
maturity, decadence, and old age leading to extinction. 

The lives of most lakes are so long that human records cover only a- 
small portion of their histories, hence their growth and decadence can 
seldom be traced by observing a single individual. By studying many 
examples, however, in various stages of development and decline, we 
are enabled to obtain separate links in the chain of their existence, and 
may determine, at least in outline, the general course that they run. By 
having the theoretical history of a normal lake in mind, one is enabled to 
determine the period of life attained by any special example that may 
be studied. 

The histories of all lakes are far from uniform. There are various 
accidents, as they may be termed, which introduce new conditions, and 
may renew their youth or hasten their decline. In general, lakes may be 
grouped in two great classes, in each of which the r61e they play is in 
the main the same. The differences in the lives of these two classes 
depend mainly on climatic conditions, and have been noticed in describ- 
ing fresh lakes and terrestrial saline lakes. The destiny of a lake born 
beneath humid skies runs in a somewhat definitely prescribed channel and 
departs in a marked way from the more varied life of a lake originating in 
an arid region. The general outline of the history of each of the twO' 
classes referred to is briefly as follows : 

Lakes of Humid Regions. — The normal lakes of humid regions 
are comparatively short-lived. The streams tributary to them bring in 
sediments which tend to fill their basins, to these are added the debris 
of water-loving plants and the hard parts of animals, and at the same 
time the streams flowing from them tend to cut down their outlets and 
drain them at lower and lower levels. Tavo processes thus conspire to 
diminish their volumes and shorten their existence. The deposition of 
sediment on their bottoms usually leads to their extinction more quickly 



THE LIFE HISTORIES OF LAKES. 91 

than the lowering of their outlets, for the reason that while incoming 
streams are frequently turbid and heavy with sediment, the outgoing 
waters are clear and therefore have but little power to erode. The clear 
outflowing waters deepen their channels by the slow process of chemical 
solution, but when the rocks over which they pass are soft and inco- 
herent, they may soon become recharged with sediment and make rapid 
progress in deepening their channels and in draining the basin above. The 
lives of various lakes may cUffer in length and have minor variations 
according to local conditions, but the main features in their histories will 
conform to the same general outline. 

The filling of lake basins by sediment frequently progresses more 
rapidly than at first might be supposed. In some instances its rate 
may be observed from year to year, and attracts the attention of even the 
casual observer. In countries that have been long inhabited, there is 
sometimes historical evidence of the rate at which the boundaries of lakes 
have contracted. At the head of Lake Geneva, Switzerland, for example, 
the Rhone is bringing in large quantities of silt derived from the gla- 
ciers on its head Avaters, and a low grade delta is being extended into the 
lake. As stated by Lyell,^ the town of Port Vallais (Portus Valespe of 
the Romans) once situated at the water's edge, is now more than a mile- 
and-a-half inland, this extension of the shore having been made in 
about eight centuries. 

The decrease in- the capacity of lake basins, in ordinary cases, goes on 
so much more rapidly from filling than from the lowering of their outlets, 
that it is the destiny of most lakes situated in humid regions to become 
exterminated mainly by sedimentation. By this process their basins are 
transformed into alluvial plains, through Avhich wander the streams that 
were tributary to the antecedent lakes. These streams being no longer 
robbed of the material they carry in suspension, are enabled to attack 
their channels below the former lakes with energy, and to deepen and 
Ijroaden them. The grade of the streams through the alluvial ])lain, 
marking the former site of a lake, is increased, and the removal of the 
soft lakebeds progresses as the channel below is deepened. Streams flow 
through alluvial plains with slackened speed, and form winding channels, 
and swing from side to side of their valleys, thus reducing the general 
level. The load previously deposited in the basin is again taken up and 
the deferred task of transporting it to the sea is resumed. Former lake- 

1 Principles of Geologj', 11th edition, 1873, vol. 1, p. 41o. 



92 LAKES OF NOETH AMERICA. 

basins thus become terraced valleys, with streams winding through them 
in broad curves, and in civilized regions afford rich farming lands and 
charming sites for towns and cities. 

At a later period, if some outside influence does not change the course 
of history, the alluvial deposits are dissected to the bottom, the terraces 
of soft material are removed, and all records of the once beautiful lake 
may be lost. This transformation may require tens of thousands of years 
for its completion, yet the end is inevitable. The various stages in this 
general history might be illustrated by an abundance of examples. Thou- 
sands of lakes in the formerly glaciated region of northeastern America 
still retain the freshness of youth, and their nearly level bottoms may be 
considered as unborn lacustral plains. The terraced borders of Lake Cham- 
plain, and of the Laurentian lakes, mark the former extent of water 
bodies that have passed the youthful stage. Many terraced valleys in the 
Cordilleras record the former presence of lakes in basins that are now 
completely drained. In other localities, as in the " Parks " of Colorado, 
no terraces may be distinguished,^ but vestiges of lacustral sediment still 
floor their bottoms. Many valleys in the same region drain through 
narrow stream-cut gorges, but all other evidence of their having been 
formerly water-filled has vanished. The time required for these muta- 
tions is vast when reckoned in years, but to the geologist they are 
transient phases in the topographic development of the land. 

The even course of history, outlined above, may be varied somewhat, 
as when the outflowing stream is rapid and especially when falls occur in 
its course. Waterfalls are formed especially where streams flow over 
nearly horizontal strata where a hard surface layer rests upon shales or 
other easily eroded beds, as is typically illustrated at the Falls of Niagara. 
The undermining of the hard capping layer is effected by the removal of 
the soft beds beneath, and blocks from the brink of the precipice fall to 
the pool below and assist the swirling water to deepen a basin. A fall 
thus cuts back the ledge over which it plunges with comparative rapid- 
ity, — in the case of Niagara the rate of recession is from 4 to 6 feet per 
year, — and may lead to the drainage of a lake before its basin has been 
deeply filled with sediment. The succession of the principal events in the 
history of a valley may thus be hastened, but the ultimate results will be 
essentially the same. 

Many small lakes, especially in forested countries, where the surface 
waters filter through layers of vegetable debris before gathering into rills 
and brooks, are filled mainly by organic agencies. Water plants, and 



THE LIFE HISTORIES OF LAKES. 93 

especially Si^hagnum or peat moss, grow about their shores, and extend- 
inof outward, form a thick mat of intertwined roots and stems that float on 
the surface. The finer waste from this sheet of floating verdure falls to 
the bottom and forms a peaty stratum. To this layer contributions are 
made by other aquatic vegetation, as the lilies, reeds, rushes, and many 
beautiful sub-aquatic plants. It also receives the trunks of trees falling 
from the shore. The small lakes of the prairie region especiall}^ are fre- 
quently transformed in this manner into beautiful fields of wild rice. In 
the central part of moss-encircled lakes, practically no mechanical sedi- 
ments are deposited, but mollusks, crustaceans, and fishes may there find 
a well sheltered home and thrive in such abundance that the bottom soon 
becomes covered with their remains. Microscopic forms also inhabit the 
water and their siliceous cases frequently accumulate so as to form thick 
layers, known as diatomaceous earth. A continuation of this process under 
favorable conditions leads to the rapid extinction of small lakes. The open 
waters are converted into bogs and swamps, on which forest trees encroach 
and still farther assist in the transformation. When these deposits of 
organic matter are di^ained, they frequently furnish rich garden lands. 
The lakes exterminated by this organic process in the diift-covered por- 
tion of North America, can only be estimated in tens of thousands, and 
probably equal in number the lakes still remaining. 

Lakes of Arid Regions. — On every continent there are broad areas 
where the skies are without a storm cloud for many months each year and 
the air is dry and hot in all but the winter season. The lakes in these 
desert regions have a different general history from their sisters whose 
banks are fringed ^^dth green vegetation and overshadowed by forests. 
Where the rainfall is small and evaporation active, the lives of lakes 
depend on delicate adjustments of climatic conditions. As the barometer 
rises and falls in harmony with changes in atmospheric pressure, so en- 
closed lakes fluctuate in sympathy with changes in humidity or in tem- 
perature. The ephemeral lives of playa lakes have already been described, 
but the larger lakes of arid regions, although subject to many fluctuations, 
may have a longer sj^an of existence than lakes of corresponding size and 
similar topographic environment in humid regions. As enclosed lakes do 
not overflow, there is no loss of area owing to the Lnvering of outlet. 
Tributary streams bring in material both in solution and in suspension, all 
of which is left as evaporation progresses, and tends to fill their basins, 
but the volume of their waters is not directly diminished l)y this process. 



94 LAKES or NORTH AMERICA. 

As their basins are filled, liowever, the waters expand and offer a greater 
surface to the atmosphere, thus promoting evaporation. A continuance 
of this process results in so enlarging the water surface that in time evap- 
oration equals the supply and the water body passes to the condition of a 
playa lake. Sedimentation may raise the water surface so that an outlet 
is found before the playa stage is reached, thus transferring an enclosed 
and saline lake to the class normal to humid regions, already considered. 

The existence of lakes in countries where there is a close adjustment 
between jDrecipitation and evaporation, is also controlled largely by topo- 
graphic conditions. It may be said that this is the primary condition that 
determines whether lakes shall exist in arid regions or not. This is true, 
if we consider the origin of the lake basins, and also important if the ex- 
istence of lakes in ready-formed basins is discussed, since the topography 
has a direct and frequently controlling influence on rainfall and on evapo- 
ration. The influence of topography is also marked in determining the 
ratio of the area of a basin to the area of the lake in its lowest depres- 
sion. The hydrographic basins of enclosed lakes as a rule are large in 
reference to their water surfaces, when compared with the ratio of catchment 
areas to lake areas in humid regions. Any change tending to diminish 
the area tributary to an enclosed lake, as the sapping of the head waters of 
its tributary streams, would have a marked influence on its history. 

Episodes of another character also occur in the lives of enclosed lakes. 
The salts slowly accumulated in them may not only be flooded out by 
overflow consequent on changes in topography, or on an increase in rain- 
fall, or on a decrease in evaporation, but may be eliminated by reason of a 
reverse change in the ratio of inflow to evaporation. A decrease in humid- 
ity or an increase in evaporation, or what is probably more frequent, a 
combination of these two processes, may reduce a lake to the playa stage. 
When this occurs, its salts will be precipitated and may become buried or 
absorbed by sediment, so that when a new lease of life is granted and the 
waters expand and form a perennial lake, they are fresh, or essentially 
so, and start anew in the process of concentration. Still other changes 
that beset the lives of enclosed lakes might be enumerated, to show that 
they are subject to greater vicissitudes than their sister lakes in more 
favored lands. 

When the lakes of arid regions become extinct, either by reason of 
evaporation or sedimentation, the evidence of their former existence 
remains inscribed on the inner slopes of their basins or concealed in the 
strata deposited over their bottoms. These records as a rule are much 



THE LIFE HISTORIES OF LAKES. 95 

more lasting than those left by lakes in humid lands, for the reason that 
the climatic conditions are less destructive. The terraces and embank- 
ments of gravel left by lakes in desert valleys are especially permanent 
topographic features, as the scant}^ rain that falls on them is absorbed and 
allowed to j)ercolate slowlj^ through them, instead of flowing down their 
surfaces so as to erode. The sediments deposited in enclosed basins are 
also protected from destruction, as they cannot be removed b}' streams 
until some change inaugurates free drainage to the sea or to some lower 
basin. A continuation of aridity in a desiccated lake basin, results 
normally in the burial of the lacustral sediments beneath subaerial 
deposits', thus again insuring their preservation. To follow tliis subject 
farther would lead to a comparative study of the processes of erosion in 
arid and in humid regions, which is beyond the scope of the present essay. 

It will be seen from what has been presented above with reference to 
the normal course of the lives of lakes, that in spite of the many varia- 
tions they present, the seeds of death are planted at their birth, and the}' 
are destined, sooner or later, to pass away and give place to other condi- 
tions. 

Interruptions of the even tenor of the lives of lakes, in both arid and 
humid regions, such as the effects of upheaval and depression of the earth's 
crust, earthquakes and volcanic eruptions, might be considered, but 
these abnormal incidents, like the accidents in human lives, cannot be 
foretold, and ajDply to individuals rather than to classes. 



CHAPTER VI. 

STUDIES OP SPECIAL LACUSTRAL HISTORY. 

It will appear to the reader of tlie preceding chapter that not only 
are lakes ephemeral features of the earth's surface, but even the changes 
they make in the topography of their shores, although perhaps engraved 
in solid rock, are of short duration in comparison with the length of the 
eras into which the earth's history has been subdivided. The lakes of 
Pleistocene times, however, left records which in many instances are still 
legible, and form a connection between historical and the most recent 
geological times. 

As examples of extinct lakes whose histories are still clearly legible, 
a brief account will be given of former water bodies of the Laurentian 
basin, and in the region now draining to Lake Winnepeg, where the 
climate is humid, and of two formerly extensive lakes of the Arid region. 

PLEISTOCENE LAKES OF THE LAURENTIAN BASIN. 

Long curving ridges of gravel having the appearance of great railroad 
embankments, following the general trend of the shores of lakes Ontario 
and Erie, but usually at a distance of several miles from their present 
borders, were noticed at an early day in the settlement of New York, 
Ohio, and Ontario, and correctly interpreted as being the records of previous 
high-water stages of the lakes they encircle. These ridges became high- 
ways of travel as civilization advanced, and gave origin to the term "ridge 
road " still to be seen on local maps of the region referred to. These 
ridges and other associated records have claimed the attention of geolo- 
gists and others and have been made the subject of special inquiry. The 
territory traversed by them is so extensive, however, that their study is 
still far from complete. 

The ancient beaches about lakes Ontario and Erie have been followed 
and studied, especially by G. K. Gilbert, in New York and Ohio, and by 
J. W. Spencer, in Canada. The records of former water levels north of 
Lake Superior from Duluth to Sault Sainte Marie, have been traced and 
mapped by A. C. -Lawson. To the south of Lake Superior the ancient 
shores have been systematically followed by F. B. Taylor. Many other 



STUDIES OF SPECIAL LACUSTEAL HISTORY. 97 

observers have also contributed to this study, but not in such a methodical 
manner as those whose names have just been mentioned. Some of the 
problems that have presented themselves during this investigation have 
not yet been satisfactorily explained, but at least an outline of the Pleis- 
tocene histor}^ of the Laurentian basin may be presented with the under- 
standing that it is to be modified as additional facts are obtained. 

The most dramatic episode in the geological historj^ of North America 
was the formation during Pleistocene time, of glaciers many hundreds of 
feet in thickness over tlie northern part of the continent. The ice advanced 
from the north and not only covered the Laurentian basin, but spread 
soutliAvard beyond the southern border of its watershed. Tlie ice covered 
this region with various advances and retreats for thousands of years, and 
when it finally withdrew, the immediate ancestors of the present Great 
Lakes were born. There are severel observations tending to the conclu- 
sion that during an intergiacial time when the ice receded far north of its 
maximum limit, lakes were formed in the same basin, but in this connec- 
tion there is little evidence to claim popular attention. 

Previous to the Glacial epoch or the Great Ice age, as it is frequently 
termed, the region under review was an old land surface with rivers flow- 
ing across it to the sea. Its drainage system was well developed and the 
streams meandered through broad valleys, bounded in part b}^ steep escarp- 
ments. In general relief, it must have resembled the upper portion of the 
Mississippi valley as it exists to-day, where the topography has not been 
modified by glacial action. 

The conclusion that the Laurentian region was exposed to erosion for 
a long period previous to the Glacial epoch, is based on the character of the 
relief of the hard rock surface now covered in part by glacial deposits and 
on the fact that no sediments of younger date than the Carboniferous 
period, with the possil^le exceptions of terranes of Cretaceous age in por- 
tions of Minnesota, occur within its borders. 

It may be suggested as a tentative hypothesis, that previous to the 
Glacial epoch the greater part of the Laurentian basin discharged its 
waters southward to the ]\Iississippi, and that during the first advance of the 
ice from the north, the drainage was not obstructed so as to form important 
lakes. This suggestion rests in part on the fact that no lake deposits 
have yet been found beneath the lowest sheet of glacial debris lining the 
l)asin, — this negative evidence is of little weight, however, as such 
deposits, if they exist, would be mostly beneath the present lakes and 
therefore exceedingly difiicnlt to discover, — and on the character of an 



98 LAKES OF NORTH AMERICA. 

ancient river valley leading south from tlie southern end of Lake Mich- 
igan, which is reported to be scored with glacial grooves, and obstructed 
by glacial deposits.^ As will be noticed below, this same channel was also 
an outlet for the waters of the Lake Michigan basin in post-glacial times. 

When the glaciers of the Glacial epoch were at their maximum, the 
drainage from the ice found a free escape southward, as is abundantly 
testified by immense deposits of gravel that were dropped by the over- 
loaded glacial streams, as well as by numerous water-worn channels which 
are too large for the streams now occupying them and are without water- 
sheds commensurate with their size. 

As the ice sheet retreated, there came a time when its southern margin 
was north of the chainage divide, passing in an irregular east and west 
direction through Central New York and Central Ohio, and now parting 
the waters flowing south from those that find their way northward to the 
Laurentian lakes. When this occurred, lakes were formed between the 
margin of the ice and the high land to the south. These earlier lakes 
stood at various levels and discharged southward across the lowest depres- 
sions in their shores. Stream channels were excavated by the outflowing 
waters and became deeply filled with gravel and sand, but in many instances 
are still clearly traceable. One of these ancient channels starts near Fort 
Wayne, Indiana, leads southwest and afforded an escape for the waters that 
accumulated in the western portion of the Erie basin. A similar outlet 
at the south end of the Lake Michigan basin has already been referred to. 
Other points of discharge have been reported at other localities on the 
southern margin of the Laurentian basin. 

As the ice occupying the Erie-Ontario basin withdrew northward, 
the lakes about its margin expanded and became united one with another. 
When the ice barrier between the two basins was broken the higher lake 
discharged into the lower one, and its former outlet leading south was 
abandoned. 

When a single water body occupied the Erie-Ontario basin, the site of 
Niagara river was deeply submerged. When the water fell to the level 
of the Mohawk outlet, the two basins became divided and Niagara river was 
born. The river from the upper basin discharged across the lowest sag- 
in its rim and cut back a deep gorge, until an old channel excavated in pre- 
glacial or possibly inter-glacial times, was discovered and the work of 
extending it renewed. When the falls shall have receded so as to drain 

1 Farther evidence seems to be needed, however, before the presence of a pre-glacial 
channel leading south from Lake Michigan, can be considered as definitely determined. 



& o 



P- o 



p- ri 




STUDIES OF SPECIAL LACUSTRAL HISTORY. 99 

Lake Erie at a lower level than at present, the shore lines now forming 
about its margin will be abandoned and another line added to the records- 
about its borders. 

For a long period in the history of the Ontario basin, the outflowing 
water escaped through the jNIohawk valley. New York, as has been shown 
by Gilbert, and the discharge of a large part of the Laurentian basin 
reached the sea by that channel. The series of well defined water-marks 
about the Ontario basin formed at this time, has been named the " Iroquois 
beach," by Spencer, and the ancient lake outlined by it is known as "Lake 
Iroquois." When the ice front retreated still farther northward, the 
present course of the St. Lawrence Avas uncovered, the Mohawk channel 
was al^andoned, the water surface fell, and existing conditions were 
established. 

During various stages in the enlargement and subsequent contraction 
of the lakes about the southern margin of the Laurentide glacier, beaches 
were formed which in some instances, as has been shown by Frank Lev- 
erett, in Ohio, are continuations of the moraines deposited at the margin 
of the ice where lakes did not exist in front of it. In other instances 
moraines occur that are partially or wholly buried beneath lake sediments 
and mark the boundaries of the ice front where it was margined by water 
bodies. 

At many localities where the former water markings are well pre- 
served, they Avere made on low shores, and took the form of ridges re- 
sembling railroad embankments. The highest of these ridges marks the 
maximum limit of the Avater body about which it Avas formed. As the 
Avater fell the higher beaches Avere abandoned and others constructed at 
leA^els determined by lower outlets. When the borders of the lakes Avere 
of ice, shore records are Avanting, but as stated above, buried moraines 
may mark the position of the dividing line betAveen the Avater and the 
confining ice. 

While the ancient beaches were in process of construction the al)un- 
dant sediments carried into the lakes, AA^ere spread out as sheets of clay 
OA'er the deeper portions of the basin, and at the same time the areas near 
shore received deposits of sand. Icebergs broke aAvay from the glaciers 
forming the northern shores of the lakes, and floated over their surfaces, 
carrying stones Avhich Avere dropped as the ice melted, and became im- 
bedded in the clay on the bottom. These deposits surround the present 
Laurentian lakes and underlie them. About the borders of Lake Erie 
they appear as a stiff blue clay, — known to geologists as the "Erie clay," 



100 LAKES OF NORTH AMERICA. 

cliarged in some instances witli large boulders of crystalline rock, — and as 
sheets of yellow sand, known as "delta sands," which rest on the clay, and 
are especially abundant where the mouths of ancient streams were located. 
About the shores of Lake Superior and frequently extending many miles 
inland, there are ancient clay deposits of a pink color, that were accumu- 
lated when the basin contained a much larger sheet of water than at 
present. 

The beaches about the borders of the Laurentian lakes were originally 
horizontal, but as has been shown especiall}^ b}^ Gilbert and Spencer, they 
are in many cases no longer in their original position. Changes in the 
elevation of the land have occurred and the beaches have been carried up 
or down with it. 

The amount of change in level shown by the warping of the beaches 
about Lake Ontario is considerable, and illustrates the character of the 
slow upheavings and subsidences known to be in progress over wide areas 
of the earth's surface. It is stated by Gilbert^ that " the old gravel spit 
_ near Toronto, belonging to what is known as the Davenport ridge, is fort}^ 
feet higher than the contemporaneous gravel spit on which Lewiston is 
built ; at Belleville, Ontario, the old shore is 200 feet higher than at 
Rochester ; at Watertown, N. Y., 300 feet higher than at Syracuse ; and 
the lowest point in Hamilton, Ontario, at the head of the lake, is 325 feet 
lower than the highest point near Watertown. From these and other 
measurements shown on Plate 18, we learn that the Ontario basin with 
its new attitude inclines more to the south and west than Avith the old 
attitudes." This general tilting has thrown the waters of Lake Ontario 
westward and flooded small tributary valleys so as to drown them and 
make miniature fiords. 

Movements in the earth's crust were also in progress during the long 
period in which the ancient lakes of the Laurentian basin were making 
their various records, as is shown by the fact that the abandoned beaches 
do not all lie in planes parallel with each other. 

The highest of the ancient beach lines about the north shore of Lake 
Superior, has an elevation of about 600 feet above the present lake, as 
has been determined by A. C. Lawson.^ The beaches at lower levels are 

1 "The history of Niagara river," in Sixth Annual Report of the Commissioners of the 
State Eeseryation at Niagara, Albany, N. Y., 1890, p. 69. Reprinted in Ann. Rep. Smith- 
sonian Institution, 1890, pp. 231-257. 

2 "Sketch of the Coastal Topography of the North Side of Lake Superior," in 20th Ann. 
Rep., Minnesota, Geol. and Nat. Hist.'Surv., pp. 181-289. 



STUDIES OF SrECIAL LACUSTRAL HISTORY. 101 

approximately parallel with it. Observations on the amount of deforma- 
tion that this beach has suffered, are not as extended as could be desired, 
but near its western extension there is evidence of a change of level of 
about one foot per mile. 

Recent observations by F. B. Taylor ^ in the region adjacent to Lake 
Supeiior on the south, have shown that ancient beaches may be clearly 
recognized at many places between Duluth and Sault Sainte Marie. The 
facts recorded by Taylor supplement in a very interesting manner the 
work of Lawson on the northern side of the same basin, although farther 
study is necessary before the entire history of the great predecessor of Lake 
Superior can be written. At the south, the highest beach has an eleva- 
tion of from 512 to 588 feet above Lake Superior, or from 1014 to 1190 
feet above the sea. 

Taylor suggests that when the entire outline of the highest beach at 
the north shall have been traced, it will be found that there were straits 
connecting the Superior basin with that of Hudson Bay. This would 
imply a submergence of a very large portion of the North American con- 
tinent to a depth of over a thousand feet. 

The erosion produced by the movement of ice sheets many hundreds 
of feet thick, over the Laurentian basin, modified and subdued the pre- 
vious relief, and the debris left when the ice melted covered the country 
with a sheet of superficial deposits to such a depth that the character 
of the underlying hard-rock topography is- only occasionally revealed. 
The depth of these glacial deposits over great areas, as in Michigan 
and Wisconsin, is from one to two hundred feet, but is probably of less 
average thickness in Ohio and New York. All pre-glacial drainage channels 
were either obstructed or obliterated and a new surface given to the land. 
The drainage was thus rejuvenated and is still immature. The effects of 
glacial plantation and of glacial deposition, in forming the basins of the 
present Laurentian lakes, has been pointed out in discussing the origin of 
lake basins. 

In this brief sketch I have endeavored to show that the history of 
the Laurentian basin includes a study of the hard-rock topography as it 
existed previous to the Glacial epoch ; the disturbances and changes in 
drainage produced by the ice invasion and by movements of elevation 
and depression ; the obstruction of the ancient waterways by glacial 
deposits ; and the origin of new channels of discharge, as the glaciers 

^ " A reconnoissance of the abandoned shore lines of the south coast of Lake Snperioi'," 
in Am. GeoL, \'ol. 13, 1804, pp. .SGo-SS.*]. See also more recent papers in the same journal. 



102 LAKES OF NORTH AMERICA. 

passed away, — all of these links in tlie complex history have not been 
completely Avorked out, and this attractive field is still open to the geolo- 
gist and geographer. 

In conclusion, it is but fair to state that while the history of the 
Laurentian basin outlined above will, I believe, be accepted as in the 
main correct by most geologists of the United States, whose attention has 
been directed to the subject, it is widely at variance with the conclusions 
of at least two Canadian geologists. Sir J. William Dawson maintains, if I 
understand his hypothesis correctly, that the sea, laden with icebergs, invaded 
the Laurentian basin in Pleistocene times, and that the moraines and other 
deposits occurring in it and over a wide extent of adjacent country, and 
believed by most observers to be of glacial origin, are shore accumulations, 
and that icebergs and floe-ice played an important part in their formation. 

The ancient beaches about the Laurentian lakes, while considered as 
true shore lines by Spencer, are thought by him to have been formed at 
sea-level during a time of continental submergence, and that the ocean 
had free access to the basin. 

It may be that in these summary statements I do injustice to the 
views of the gentlemen referred to, but the conclusions indicated are so 
widely at variance with a vast body of consistent evidence gathered by a 
score or more of skilled observers, and is so directly opposed to my own 
observations, both of living glaciers and of the records of past glaciation, 
that they do not seem at present to be open to profitable discussion. 

A subsidence of the eastern border of the continent during the later 
stages of the Glacial epoch, or following its close, throughout a belt 
widening from New York city northward, and including the valley of 
Lake Champlain, is well known. When the studies leading to this con- 
clusion are extended to the basins of the Laurentian lakes, however, not 
only is there an absence of salt-water shells and other evidences of marine 
occupation, but, seemingly, positive evidence of lacustral condition. 

The region to the north of Lake Superior has not been sufficiently 
studied to admit of an opinion being reached in reference to the questions 
just considered, from the records there obtained. It may be found that 
the highest shore-line in the Superior basin was formed by a water body 
in direct communication with the sea to the north, as suggested by 
Taylor. Should this hypothesis be sustained, it would add an interesting 
chapter to the history of the Superior basin, and render a review desirable 
of the evidence of a similar nature in the eastern portion of the region 
now drained by the St. Lawrence. 



STUDIES OF SPECIAL LACUSTRAL HISTORY. 103 

The views of Dawson and Spencer are set forth in the publications 
mentioned in the following footnote, ^ and should be attentively studied 
by all who undertake to read the history of the Laurentian basins from 
the original records in order that their conclusions may be fairly tested. 

Lake Agassiz. 

At the time the remarkable changes described above Avere taking place 
in the Laurentian basin, there were corresponding revolutions in the 
geography of the region to the northwest which now cbains to Lake 
Winnepeg and thence through Nelson river to Hudson bay. 

It will be readily seen on glancing at a map of Canada, that if a 
glacier of the continental type should advance southward from the Hud- 
son bay region, the drainage would be obstructed and a lake formed over 
the country of mild relief surrounding Lake Winnepeg and the Lake of 
the Woods, and extending southward through the Red River vallej'', far 
into ]\Iinnesota. Such a lake would discharge southward, and contribute 
its surplus waters to the Mississippi. Should the hypothetical glacier re- 
ferred to advance until it occupied all of the Winnepeg basin, the lake 
about its southern margin would be obliterated, and there would be free 
drainage to the Gulf of Mexico. Should the glacier then retreat to the 
north of the divide now separating the waters flowing southward to the 
Gulf of Mexico from those flowing northward to Hudson bay, a lake would 
be born about the margin of the ice, and would increase northward as the 
ice retreated. When a channel leading northward was uncovered and 
rendered available as an outlet for the lake, the ponded waters would have 
their level lowered and their area contracted. 

The study of the Pleistocene records in the Red River valley and 
thence northward in Manitoba, has shown that changes very similar to 
those postulated above actually occurred. 

The evidence of the former existence of a large lake in the Red River 
valley was observed as far back as 1823 by Keating, the geologist of the 
first scientific expedition to that region. Subsequent contributions to this 
investigation have been made by several observers, and notably by 

1 J. W. Dawson, "The Canadian Ice Age," Montreal, 1803; J. W. Spencer, "The De- 
formation of Iroquois Beach and Birth of Lake Ontario," in Am. Jour. Sci., ser. S, vol. 40, 
1890, pp. 443-451 ; J. "W. Spencer, "Deformation of the Algonquin Beach and the Birth of 
Lake Huron," in Am. Jour. Sci., ser. 3, vol. 41, 1891, pp. 12-21; J. W. Spencer, "Post- 
Pleistocene Subsidence versus Glacial Dams," in Geol. Soc. Am. Bull., vol. 2, 1891, pp. 
4G5-474. 



104 LAKES OF NORTH AMERICA. 

Gen. G. K. Warren, who first explained the origin of the valley now 
occupied by Lake Traverse, Big Stone lake, and the Minnesota river, by 
showing that it was excavated by a stream flowing to the Mississippi 
from a former lake to the north. This ancient river, whose source has 
long since been sapped by northward drainage, has been named River 
Warren, after its discoverer. 

The great lake that formerly flooded the Winnepeg basin, and during 
its highest stage overflowed through River Warren, has been named Lake 
Agassiz, by Warren Upham, in honor of Louis Agassiz. Practically all 
of the facts and conclusions here presented concerning the history of that 
remarkable lake, have been made known through the long-continued and 
skillful investigations of Upham, under the auspices, at different times, 
of the geological surveys of Minnesota, the United States, and Canada, ^ 
respectively. 

The Red River of the North rises in the western part of Minnesota, 
and receives the tribute of Lake Traverse, situated on the Minnesota- 
Dakota boundary, and at the southern limit of the country formerly 
flooded by Lake Agassiz. From Lake Traverse the present drainage is 
northward through narrow channels sunken in the sediments of the 
former lake. Between the streams there are broad, nearly level, inter-r 
stream spaces, forming typical examples of new-land areas, on which 
shallow ponds form during rainy seasons. About the borders of this 
broad, level extent of prairie land, now transformed into wheat fields, 
there are gravel ridges which mark the surface level of the former lake at 
various stages. These ancient beaches have been traced northward and 
found to diverge toward the northeast and northwest when the central 
area of the old lake was approached, and have been mapped so as to show 
approximately the extent, of the water body that built them. By patiently 
following these ancient shore-lines, it has been demonstrated that Lake 
Agassiz covered a region about 110,000 square miles in area. Its 
diameter from north to south was 675 miles, and from east to west, in the 
wider portions, varied from 225 to 300 miles. It was the largest of the 
Pleistocene lakes of North America thus far discovered, and exceeded the 
combined areas of the present Laurentian lakes. The rim of its hydro- 
graphic basin embraced a region not less than half a million square miles in 
area. At the site of Lake Winnepeg the ancient lake was 600 feet deep. 

1 A report on these investigations appeared in the Geol. and Nat. Hist. Survey of Canada, 
Ann. Eep., vol. 4, 1888-9, pp. 1-156 E, and a monograph on the same subject is soon to be 
issued by the U. S. Geol. Survey. 



STUDIES OF SPECIAL LACUSTKAL HISTOUV. 105 

One of the most interesting discoveries in connection with the beaches 
of Lake Agassiz, is that they are no longer horizontal, and besides do not 
lie in plains that are parallel one with another. The highest water line 
when followed northward has been found to rise at the rate of 200 feet in 
300 miles. There are five beaches that are especially prominent and 
mark a lingering of the lake surface at their respective horizons. The 
hio-hest of the series, known as the Heiman beach, when traced northward 
from the southern end of the Red River valley, has been found to divide 
into several beaches at different levels ; the vertical intervals between the 
division increasing northward. The meaning of this fact seems to be that 
the land was rising at the north at the time the beaches were formed and 
at the same time the surface of the lake was lowered by reason of the 
opening of new outlets. 

To the north of Lake Winnepeg the higher of the ancient beaches are 
absent and the lower ones difficult to trace. • The country still farther 
toward Hudson bay is low and does not present a barrier that under any 
plausible hj-pothesis could have been made to act as a dam to retain the 
waters of Lake Agassiz. What then could for a time have reversed the 
drainage and led to the formation of a lake over a hundred thousand 
square nliles in area ? 

The origin of Lake Agassiz as explained by LTpham, is in harmony 
with the history of the former lakes of the Laurentian basin. It is sup- 
posed to have owed its origin to the presence of a vast ice sheet over the 
Hudson bay region which dammed the northward drainage of the Winne- 
peg basin and caused the waters to rise until an outlet was found at the 
south and River Warren began to floAv. When the ice retreated, new 
outlets at lower levels became available at the north and the waters fell, 
but lingered for a time at the horizon of each of the various beaches that 
have been referred to, at lower levels than the Herman beach. 

There are facts in connection with the ancient floods of the Laurentian 
and Winnepeg basins, which seem to indicate that the Aveight of the ice 
during the Glacial epoch caused the land to subside, and that when the 
ice melted an ujiward movement was initiated. These movements, and 
also the attraction of tlie ice body to the north of Lake Agassiz, have 
been thought to explain the gradual rise of the beaches when traced 
northward. 

The strange transformation that the Winnepeg basin underwent in 
Pleistocene times, leads one to wonder if in the region now di'ained by 
Mackenzie river, and occupied in part l)y Great Slave and Great Bear 



106 LAKES OP NORTH AMERICA. 

lakes, there may not be equally wonderful records awaiting the coming of 
the patient inquirer. 

Pleistocene Lakes of the Great Basin. 

During the time of great climatic changes that Avitnessed the birth, 
growth, and decadence of the great lakes of the Laurentian and Winnepeg 
basins, described above, equally important fluctuations occurred in the 
lakes of the Arid region. Many of the valleys of Utah and Nevada, and 
of adjacent areas both north and south, that are now parched and desert- 
like throughout the year, were then flooded, and in some instances filled 
to the brim so as to overflow. All of the enclosed lakes west of the Rocky 
mountains were then of greater size than at present and underwent marked 
changes in sympathy with the advance and retreat of glaciers on neighbor- 
ing mountains, and had their oscillations controlled by the same causes, 
viz., variations in precipitation, evaporation, and temperature. 

Of these numerous water bodies there were two of broad extent which 
may be taken as types of their class and will serve to give an epitome of 
the history of their time. The two ancient lakes referred to are Bonne- 
ville and Lahontan^ and are represented on the map forming Plate 19. 

Lake Bonneville was named by Gilbert in honor of Captain B. L. E. 
Bonneville, U.S.A., who made a bold exploration into the wilds of the 
Rocky mountains in 1833, and was the first person to gather reliable 
information concerning the region formerly occupied by the great lake 
now bearing his name. The reader will perhaps have an additional 
interest in the following sketch, when he recalls the "Adventures of 
Captain Bonneville," so graphically described by Washington Irving. 

Lake Lahontan first received definite recognition in the reports of the 
40th Parallel survey under the direction of Clarence King, and was named 
after Baron LaHontan, one of the early explorers of the Mississippi valley. 
Why LaHontan's name should have been thus connected with a region 
more than a thousand miles beyond his farthest camp, in preference to 
the names of men who boldly crossed and recrossed the land referred to 
when it was a trackless desert infested with roving bands of savages, I 
must leave to others to explain. 

As shown on the accompanying map, Plate 19, Lake Bonneville occu- 
pied the basin in which Great Salt lake now lies, on the east side of the 

1 Clarence King, U. S. Geol. Exploration of the 40tli Parallel. Vol. 1, 1878, pp. 490-529. 
— G. K. Gilbert, "Lake Bonneville." U. S. Geol. Surv., Monograph No. 1, 1890. -L C. 
Russell, "Lake Lahontan." U. S. Geol. Surv., Monograph No. 11, 1885. 



Lakes of North America. 



Plate 19. 




PLEISTOCENE LAKES OF THE GREAT BASIN. 
Tliis map is incomplete, as the entire area lias not been studied. 



STUDIES OF SPECIAL LACUSTRAL HISTORY. 107 

Great Basin, while Lake Lahontan flooded a series of irregular valleys on 
the west side of the same great area of interior drainage and is now repre- 
sented by Pyramid, Winnemucca, Walker, Carson, and Humboldt lakes, 
Nevada, and by Honey lake, California. 

These two ancient lakes were contemporaries, and, although differing 
in their histories, bear similar testimony in reference to climatic changes 
and supplement each other's records in a remarkable manner. Their 
hydrographic basins joined each other in north-eastern Nevada, for a 
distance of about twenty-five miles, and together occupied the entire 
width of the Great Basin. Lake Bonneville received its water supply 
from the Wasatch and Uinta mountains, then snow-clad throughout the 
year and holding glaciers of the Alpine type in many of their valleys. 
Several of the ice streams on the precipitous western slope of the Wasatch 
mountains reached nearly to the ancient lake which washed the base of 
the range, and one of them was prolonged for a short distance into its 
waters. Lake Lahontan derived its principal water supply from the Sierra 
Nevada, which formed the western rim of its drainage basin for a distance 
of 250 miles, and, like the eastern borders of the Bonneville basin,' was 
glacier-covered. 

Lake Bonneville at the time of its maximum extension had an area of 
19,750 square miles, and a hydrographic basin 52,000 square miles in 
area. The more irregular water surface of Lake Lahontan was 8,422 
square miles in area, and occupied the lowest depressions in a hydro- 
graphic basin containing 40,775 square miles. The great size of the 
hydrographic basins of these lakes in comparison with their extent of 
water surface, is a noteworthy feature. The ratio of the extent of lake 
surface to area of h^^drographic basin in the case of Lake Bonneville was 
as 1 to 2.6, and in the case of Lake Lahontan about 1 to 5. The corre- 
sponding ratios in the basin of Lake Superior are as 1 to 1.72 ; and for 
the combined Laurentian lakes as 1 to 3.19. The small extent of the 
ancient lakes of the Great Basin in comparison with the areas draining to 
them, more especially in the case of Lake Lahontan, indicates that the 
climate of their time was not markedly humid. 

The maximum depth of Lake Bonneville as recorded by beach lines 
on the mountain forming its shores, and on the precipitous islands now 
rising in Great Salt lake, was 1050 feet. The greatest depth of Lake 
Lahontan was 886 feet. 

The most striking difference in connection with these two ancient 
seas is in reference to overflow. The waters of Lake Bonneville rose 



108 LAKES OF NOETH AMERICA. 

until they found an outlet and escaped through a channel leading north- 
ward from Cache valley, in Utah and Idaho, to Snake river and thence to 
the Columbia. The outflowing stream at its source crossed incoherent 
alluvial deposits and rapidly cut down a channel of discharge to a depth 
of 370 feet, thus lowering the lake by that amount. During this episode 
in its history the lake was fresh, but at later stages, when its surface fell 
below the level of the bottom of the channel of discharge, it became 
saline". The water supply of Lake Lahontan was less abundant and it 
never rose so as to find an outlet. Its waters were perhaps brackish 
during its higher stages, and became saline and alkaline as concentration 
progressed. 

Each of these lakes had two high-water stages, separated by a time of 
low water and probably of complete desiccation. The second high-water 
stage in each instance was the more marked of the two. These fluctua- 
tions are indicated in the following diagram of the rise and fall of Lake 
Lahontan. 

Each lake spread out two sheets of fine, evenly-laminated clays, sepa- 




FlG. 8. — DlAGEAJI SHOWING THE ElSE A>D FALL OF LAKE LAHOXTAIf. 

rated, at least about their borders, by deposits of coarse gravel and sand 
washed in from the adjacent slopes during the inter-lacustral time of low 
water. 

There are many reasons for concluding that the two high-water stages 
recorded by beach lines and by sedimentary deposits in the basins of lakeS 
Bonneville and Lahontan, correspond in time with two of the periods of 
glaciation recorded in the Laurentian basin. Two periods of marked 
advance separated by a time of retreat, are also indicated by the glacial 
records in the canons of the Sierra Nevada. 

The waters of both Bonneville and Lahontan underwent many minor 
fluctuations of level as is the rule with all enclosed lakes. The terraces, 
embankments, deltas, etc., constructed about the shores of Lake Bonne- 
ville are on a grander scale than in the basin of its companion lake, for 



STUDIES OF SPECIAL LACUSTIIAL HISTORY. 109 

the reason that it was the hxrger of the two water bodies and had a more 
reguhir ontline, thus giving the wind a better opportunity to act on its 
waters, and also because it was hehl at a definite level for a long period, 
or rose to the same horizon at various times, on account of its having an 
outlet. 

The highest water line about Lake Bonneville, named the " Bonneville 
beach," is conspicuous not so much on account of its strength as for the 
reason that it marks the dividing line between rain sculpture 0]i the 
higher portions of the bordering mountains and the characteristic topogra- 
phy due to the work of waves and currents on their lower slopes. The 
channel of discharo-e Avas lowered until a sill of resistant limestone was 
reached wliich determined the horizon of the strongest and best developed 
terraces and embankments in the basin. A well defined beach at this 
horizon is known as the " Provo beach," the name being derived from the 
town of Provo, Utah, which stands on a broad delta formed by the sedi- 
ment of Provo river, when the lake stood at the horizon of its lowest 
point of discharge. The wave-built structures marking the Provo stage 
are on a magnificent scale and are still almost as fresh in appearance and 
perfect in form as if abandoned by the waves but yesterday. In the 
Lahontan basin the shore topography was never strongly pronounced. 
Fluctuations of level were not controlled by an outlet, and the numerous 
islands and headlands diminished the influence of the wind and checked 
the action of waves and currents. 

The chemical histories of lakes Bonneville and Lahontan are fully as 
instructive and of as great interest as their physical changes. In this 
connection, the basin of Lake Lahontan has been found to exceed its 
companion in the completeness of its records. The escape of the waters 
of Lake Bonneville insured its freshness during a part of its history. The 
absence of an outlet for the Avaters of Lake Lahontan led to a high degree 
of concentration. 

When lake waters are concentrated by evaporation the first substance 
to be precipitated, as previously described, is calcium carbonate. About 
the shores of Lake Bonneville there are in favorable localities, consider- 
able deposits of this substance in the form of coral-like incrustations 
known as calcareous tufa. It appears on rocky points and forms a cement 
for gravel and sand on the outer borders of some of the terraces, but is 
insignificant in amount and simple in character, when compared with 
the truly immense accumulations of a similar nature in the Lahontan 
basin. 



110 LAKES OF NOETH AMERICA. 

The precipitation of calcium carbonats from lake waters takes place 
principally in two ways ; it may separate in the open lake and fall to the 
bottom in a finely divided state and become mingled with mechanical 
sediments so as to form marls, or it may be precipitated where solid 
rocks occur and cover them with a dense incrustation. The ability of 
ordinary surface waters to dissolve calcium carbonate, depends mainly on 
the carbonic acid gas they hold in solution. Lake waters lose their dis- 
solved gases most rapidly where they form breakers along the shore, as in 
such instances they are most thoroughly aerated. For this reason, the 
boldest headlands are apt to receive the heaviest deposits of tufa when the 
waters dashed against them became concentrated. It is at such localities 
that the principal deposits of tufa in the Bonneville basin occur. It 
happens also that calcium carbonate has a tendency to accumulate about 
solid bodies, not only because they afford a stable support, but for the 
additional reason that points and angles induce crystallization. Calcareous 
tufa was deposited in vast quantities about the shores of Lake Lahontan 
wherever there were rocky slopes and in increasing abundance from an 
horizon high up on its borders down to the deepest point now exposed. 
The fluctuations of level in Lake Bonneville were recorded principally by 
beaches and embankments of mechanical origin ; similar changes in Lake 
Lahontan are made known by tufa deposits of chemical origin. 

The tufa of the Lahontan basin presents three main varieties, each of 
which is composed of concentric layers as is shown in Plate 21, The 
smaller divisions seem to indicate minor changes in the chemistry, and 
perhaps also fluctuations in the temperature, of the water from Avhich they 
were precipitated. The three principal varieties have been named in the 
order of their formation, Lithoid, Thinolitic, and Dendritic tufa. Lithoicl 
tufa is a compact stou}^ substance with a granular texture ; Dendritic tufa 
has an open structure and resembles a mass of branching twigs turned to 
stone ; and Thinolitic tufa, shown in Plate 22, is composed of well 
defined crystals to which the name Thinolite was given b}'- Clarence 
King. The composition of each of these varieties is the same. They are 
composed of calcium carbonate with usually some slight amount of im- 
purities. Their wide variation in structure and general appearance, is 
due to differences in the condition of the lake waters at the time of 
their formation. 

About Pyramid lake, where the Lahontan tufas are usually well dis- 
played, the first or Lithoid variety reaches a height of 600 feet, the Thino- 
litic 110 feet, and the third or Dendritic variety, 320 feet above the 



Lakes of Nokth Ameeica. 



Plate 20. 




TUFA TOWERS ON THE SHORE OF PYRAMID LAKE, NEVADA. 



STUDIES OF SPECIAL LACUSTEAL HISTORY. Ill 

surface of the present lake. The relation of the tufa deposits and the 
terraces witli which they are associated, are shown in the following diagram. 



Lahontan Beach 530 feet. 

Litlioid Terrace 500 " 

Dendritic Terrace 320 " 



Thinolitic Terrace 110 

Surface of Pyramid Lake, 1882 . . 



Fig. 9. — Diage.oi showing the relation of the Terraces of Lake Lahontan 
TO Pyramid Lake. 

The Lithoid tufa near its upper limit is seldom over eight or ten 
inches thick, but increases to ten or twelve feet on the lower slopes. The 
Thinolite is usually from six to twelve feet thick. The Dendritic variety 
is the heaviest of all and frequently appears on steep slopes in imbricated 
laj^ers from fifty to sixty feet thick. In some favorable locality the entire 
tufa deposits have a thickness of at least eighty feet, and in rare places 
near the surface of Pyramid lake and partially concealed by its waters, 
there is evidence that these deposits are still more massive. The total 
amount of calcium carbonate deposited from the ancient lake can only be 
estimated in millions, if not billions of tons. 

Every island and rocky crag that rose in Lake Lahontan became a cen- 
ter of accumulation for tufa deposits and was transformed into strange and 
frequently fantastic shapes by the material precipitated upon it. Now 
that the waters of the ancient sea have disappeared, these structures stand 
in the desert valleys like the crumbling ruins of towers, castles, domes, and 
various other shapes, in keeping with the desolation surrounding them. 
The finest examples of these water-built structures, some of them a hun- 
cbed feet or more in height, occur about the border of Pyramid and 
Winnemucca lakes (Plate 20), or rising from their bottoms and still 
wholly or in part submerged. The islands in Pyramid lake are sheathed 
from base to summit with these deposits and their precipitous sides given 
a convex outline, owing especially to the vast deposits of Dendritic tufa, 
which was precipitated most abundantly midway up the slopes. The 
most remarkable of these islands, and the one from which the lake derives 
its name, is shown in the sketch forming Plate 23. When the tufa towers 
and castle-like piles are broken, the concentric layers of which they are 
composed are revealed and fill one with wonder at the vast amount of 
material they contain, as well as attract the eye on account of the delicacy 



112 LAKES OF NOETH AMERICA. 

and beauty of their structure. Nowhere else in this country, and so far 
as reported, nowhere else in the world, are rocks formed of precipitates 
from lake waters so magnificently displayed as in the desert valleys of 
Nevada. 

The fascination of the weird and frequently AvonderfuUy impressive 
scenery of the region formerly submerged beneath the waters of Lake 
Lahontan, is enhanced, at least to the geologist, by the fact that there is 
yet an unsolved mystery connected with the tufa deposits that start out 
as strange, gigantic forms from the desert haze, as one slowly traverses 
those bitter, alkaline lands. 

It is believed that we understand how the more compact and stone- 
like variety of tufa was deposited, since similar accumulations are formed 
where waters saturated with calcium carbonate deposit that salt on account 
of the loss of carbonic acid. The Dendritic tufa may also have been pre- 
cipitated in a similar manner, or perhaps through the agency of low forms 
of plant life. The mode of origin of the tufa with Avell-defined crystals, 
however, is still unknown, although both geologists and chemists have 
sought diligently to discover the secret of its formation. The open cellu- 
lar structure of the crystals, as well as their forms, suggest that they are 
pseudomorphs, that is, having a false form, or a form not assumed by cal- 
cium carbonate on crystallizing, but resulting from the alteration or 
replacement of some other mineral. This suggestion only removes the 
difficulty one stej) farther, however, since the nature of the original min- 
eral is still unknown. A more definite statement of this problem may be 
found in a special report on Thinolite, by E. S. Dana, Avho has put the 
matter in a clearer light than had previously been done.^ 

One of the most remarkable facts in connection with the history of the 
Lahontan basin, is that the present lakes within it, which might be sup- 
posed to be remnants of the ancient water-body left by incomplete evap- 
oration, and therefore intensely saline, are in reality scarcely more than 
brackish. As shown in the table of analyses of saline lakes given on 
page 72, Pyramid, Winnemucca, and Walker lakes, the representative 
water bodies now existing in the Lahontan basin, carry only a small frac- 
tion of one per cent of saline matter in solution. We know that Lake 
Lahontan did not overflow. All of the saline matter carried into it, 
therefore, must still be retained in its basin. The vast quantity of vari- 
ous salts, and especially of sodium chloride, sodium sulphate, and sodium 

1 " Crystallographic Study of the Thiuolite of Lake Lahontan," Bulletin No. 12, U. S. 
Geol. Survey. 



o 




STUDIES OF SPECIAL LACUSTRAL HISTORY. 113 

carbonate tlius concentrated, is indicated by the weight of the calcareous 
tufa lining the basin. In orchnarj- river waters, as already shown, the 
calcium carbonate is about the same as the amount of all other salts in 
solution. It follows, therefore, that the more soluble salts contributed to 
Lake Lahontan must have been equal in weight to the tufa deposits just 
described. Such a vast quantity of saline matter, if contained in the 
present lakes, would make them concentrated brines. The question is, 
what has become of the more soluble salts contributed to the waters of the 
ancient sea? 

A lake may occasionally evaporate to dryness, or exist as a playa lake 
for a long period, that is, expanding during rainy seasons and becoming 
desiccated either during dry seasons, or occasionally in years of unusual 
aridit3^ Under such conditions its contained salts would be precipitated 
and become buried or absorbed b}^ mechanical sediments, so that when 
a change of climate permitted the existence of a perennial lake in the 
same basin, it would be fresh, or essentially so. This is what seems to 
have occurred in the Lahontan basin. The old lake was probably evapor- 
ated to dryness and the precipitated salts buried beneath playa clays, and 
when a change to slightly more humid conditions permitted of the birth 
of the present lakes, a new cycle was begun. 

From analyses of the waters flowing into the present lake of the 
Lahontan basin, it has been estimated that under existing conditions they 
would acquire their present degree of salinity in about 300 years. It 
seems to follow from this study that during a long term of years, ending 
about 300 years ago, the climate of Nevada was so intensely arid that no 
perennial lakes could exist within her borders. 

An account of the phj^sical and chemical histories of the ancient lakes 
of Utah and Nevada should be followed by a description of the plants and 
animals that found a home on their shores, but unfortunately our informa- 
tion in this connection is vague. 

The sediments of lakes Bonneville and Lahontan, unlike many other 
lake-beds, are extremely poor in vegetable fossils. As the conditions for 
the preservation of such remains were favorable, and as an extended 
search has failed to unearth so much as a single leaf or a single water- 
logged tree-trunk from their sediments, it may reasonably be concluded 
that their shores were not forested, and were probably even more barren 
and desolate than at the present da}-. This result cannot be considered 
as surprising in view of the great fluctuation of climate that the Great 
Basin experienced in Pleistocene times. 



114 LAKES OF NORTH AMERICA. 

Of the remains of vertebrates, the bones of the mastodon or mammoth, 
and of the ox, camel, and horse have been found in the sediments of Lake 
Lahontan, together Avith a single undetermined fish. The bones of a 
musk-ox were obtained near Salt Lake City under such conditions that it 
is believed they were buried in the upper strata of the Bonneville sedi- 
ments. The basins of contemporaneous lakes in Oregon, have yielded 
vertebrate fossils more abundantly, but concerning these there are differ- 
ences of opinion as to their age. It is probable that some of them at least, 
and perhaps the larger portion, were washed out of older deposits and 
accumulated in the basin where they are now found. 

Li the sediments of both Bonneville and Lahontan there are many 
species of fresh-water shells, but these are usually small individuals, and 
appear to have lived under uncongenial conditions. 

The remains of animal life do not seem to point to any very definite 
conclusion. We are led to believe from all of the evidence available, 
however, that the climate of the lake period was cold and changeable, 
and consequently uncongenial to either plant or animal life. The inter- 
lacustral epoch was probably a time of high temperature and aridity. 
The large animals whose bones have been discovered may have been 
forced to migrate owing to wide-reaching climatic changes, and were per- 
haps only temporary visitors to the region where they succumbed to ad- 
verse conditions. 

The mastodon and mammoth roamed over nearly the whole of North 
America during Pleistocene times, but have since become extinct. The 
camel is no longer found on this continent, and the horse was extinct 
before the coming of the white man. The musk=ox is now found only 
far to the north. The extinction of some of these large animals, and 
the scattering of others to distant regions, suggests the lapse of a long 
period of time since they lived together where their remains are now 
found, and also points to great changes in climatic and other elements of 
their environment. 

Of the presence of man on the shores of lakes Bonneville and Lahon- 
ton the records are silent. 

Lakes of the Remote Past. 

The presence of the bones of large animals in the sediments of lakes 
Bonneville and Lahontan naturally leads one to look farther back in 
the earth's history, to the deposits of other lakes from which a vast 



STUDIES OF SPECIAL LACUSTEAL HISTORY. 115 

menagerie of strange and frequently gigantic forms have been made 
known by the hibors of American paleontologists. 

Immediately preceding the " Great Geological Winter," as the Glacial 
epoch has been termed, when half of the North American continent was 
sheathed in ice, there was a period of genial climate when vegetation, as 
varied and beautiful as that of the Mississippi valley to-day, extended far 
north and reached the vicinity of the pole itself. During different epochs 
in this geological summer, known as the Tertiarj^ period, vast fresh-water 
lakes existed in the Cordilleran region, several of which Avere far more 
extensive than any lakes now known. In some of these vast inland seas 
several thousand feet of sediments were laid down. In these deposits 
we find in abundance the impressions of leaves that were blown from the 
land, or washed in by tributary streams, and the bones of many large 
mammals, whose homes were alouQ- the lake shores and on neisfhborino- 
forest-covered hills. 

All trace of the shore topography of the Tertiary lakes has disap- 
peared, and in many instances the beds of sand, clay, and volcanic dust 
deposited over their -bottoms have been upheaved into mountain ranges, 
and deeply dissected by erosion. Their histories can only be deciphered 
from the records in their sediments. Their story deals largely with the 
structure, habits, and development of vertebrate animals, and must be left 
to those skilled in that branch of study. 

Beyond the Tertiary period, and so remote from our own time that 
humble forms of mammalian life had only just appeared on the earth, 
were the Jurassic and Triassic periods. In this Mesozoic time, or middle 
age of the earth, lakes also existed, and, in their sediments the skeletons of 
another striking and grotesque assemblage of strange forms were pre- 
served. The magic wand of modern science has brought fortli from these 
long-silent tombs a wonderful procession of gigantic reptiles, the like of 
which has not since existed on the earth. 

Still more remote were the lakes and swamps of the Carboniferous 
period. The oldest records of air-breathing vertebrates yet discovered are 
the bones of reptiles found by Dawson in hollow-tree trunks that stood in 
the fresh-water swamps of Nova Scotia during the time our continent was 
green with the ferns and elub-mosscs of tlie Goal period. With these bones 
are mingled the shells of land-snails, the earliest of tlieir class yet found. 

In deposits of cannel coal formed in fresh-water ponds in the great 
coal swamps of Ohio, Newbery discovered a large number of species of 
fishes and amphibians, in a Ijeautiful state of preservation. 



116 LAKES OF NOKTH AMERICA. 

Farther back still in the records of the past are other fragments of the 
earth's history sealed up and preserved in lake deposits. The heavy beds 
of sandstone composing the Catskill mountains, and forming a part of the 
Devonian system, contain shells which resemble the covering of fresh- 
water moUusks, and may indicate that the sands in which they were 
buried are of lacustral origin. Here the evidence of terrestrial lakes 
seems to end. What inland water bodies existed in remote Silurian, 
Cambrian, and Algonkian times, remains to be discovered. 



Lakes of Kortii A.^ierica. 




A CHARACTERISTIC SPECIMEN OF THINOLITE. 



SUPPLEME]N'T. 



The adyaiice made in the study and in the interpretation of the meaning 
of topographic forms, has been so great, especially in America, during the 
present decade, that I am sure the reader Avill be interested in the writings of 
those Avho have made this important departure from old methods. The recog- 
nition that lakes are transient features of the ever-changing earth's surface and 
come and go during cycles of topographic development, was first clearly set 
forth in a brief paper by W. M. Davis, ^ Avhich is here reproduced. 

The Classification' or Lakes. 

Several years ago I presented to the Boston Society of Natural History a 
paper on the classification of lake-basins, in which the many varieties of lakes 
were grouped under three heads, according as they were made by constructive, 
destructive, or obstructive processes. The first heading included lakes made 
by mountain-folding and other displacements ; the second consisted chiefly of 
basins of glacial erosion ; the third contained the greatest number of varieties, 
such as lakes held by lava, ice, and drift barriers, delta and ox-bow lakes, and 
some others. The classification proved satisfactory, in so far as it suggested 
a systematic arrangement of all kinds of lakes that have been described ; but 
it now appears unsatisfactory, inasmuch as its arrangement is artificial, with- 
out reference to the natural relations of lakes to the development of the drain- 
age systems of which tlie}^ are a part. A more natural classification is here 
presented in outline. 

When a new land rises from below the sea, or when an old land is seized 
by active mountain-growth, new rivers establish themselves upon the surface 
in accordance with the slopes presented, and at once set to work at their long 
task of carr3-ing away all of the mass that stands above sea-level. At first, 
before the water-ways are well cut, the drainage is commonly imperfect : 
lakes stand in the undrained depressions. Such lakes are the manifest signs 
of immaturity in the life of their drainage sj'stem. We see examples of them 
on new land in southern Florida; and on a region lately and actively dis- 
turbed in southern Oregon, among the blocks of faulted country described by 
Eussell. But as time passes, the streams fill up the basins and cut doAvn the 
barriers, and the lakes disappear. A mature river of uninterrupted develop- 

1 Science, vol. 10, 1887, pp. 142, 143. 



118 SUPPLEMENT. 

raeiit has no such immature features remaining. The life of most rivers is, 
however, so long, that few, if any, complete their original tasks undisturbed. 
Later mountain-growth may repeatedly obstruct their flow ; lakes appear 
again, and the river is rejuvenated. Lake Lucerne is thus, as Heim has shown, 
a sign of local rejuvenation in the generally mature Keuss. The head waters 
of the Missouri have lately advanced from such rejuvenation; visitors to the 
Kational Park may see that the Yellowstone has just regained its former 
steady flow by cutting down a gate through the mountains above Livingston, 
and so draining the lake that not long ago stood for a time in Paradise valley. 
The absence of lakes in the Alleghany mountains, that was a matter of sur- 
prise to Lyell, does not indicate any peculiarity in the growth of the moun- 
tains, but only that they and their drainage system are very old. 

The disappearance of original and mountain-made lakes is therefore a sign 
of advancing development in a river. Conversely, the formation of small 
shallow lakes of quite another character marks adolescence and middle life. 
During adolescence, when the head-water streams are increasing in number 
and size, and making rapid conquest of land-waste, the lower trunk-stream 
may be overloaded with silt, and build up its flood-plain so fast that its smaller 
tributaries cannot keep pace with it : so the lakes are formed on either side of 
the Red Eiver of Louisiana, arranged like leaves on a stem ; the lower Danube 
seems to present a similar case. The flood-plains of well-matured streams 
have so gentle a slope that their channels meander through great curves. 
When a meander is abandoned for a cut-off, it remains for a time as a cres- 
centic lake. When rivers get on so far as to form large deltas, lakes often 
collect in the areas of less sedimentation between the divaricating channels. 
Deltas that are built on land where the descent of a stream is suddenly 
lessened and its enclosing valley-slopes disappear, do not often hold lakes on 
their own surface ; for their slope is, although gentle, rather too steep for that : 
but they commonly enough form a lake by obstructing the stream in whose 
valley they are built. Tulare Lake in southern California has been explained 
by Whitney in this way. 

The contest for drainage area that goes on between streams heading on the 
opposite slopes of a divide sometimes produces little lakes. The victorious 
stream forces the divide to migrate slowly away from its steeper slope, and 
the stream that is thus robbed of its head waters may have its diminished 
volume clogged by the fan-deltas of side-branches farther down its valley. 
Heim has explained the lakes of the Engadine in this way. The Maira has, 
like an Italian brigand, plundered the Inn of two or more of its upper streams 
and the Inn is consequently ponded back at San Moritz and Silvaplana. On 
the other hand, the victorious stream may by this sort of conquest so greatly 
enlarge its volume, and thereby so quickly cut down its upper valley, that its 
lower course will be flooded with gravel and sand, and its weaker side-streams 



SUPPLEMENT. 119 

ponded back. • Xo cases of this kind are described, to my knowledge, but they 
will very likely be found ; or at least we may expect them to appear when the 
northern branches of the Indus cut their way backwards through the inner- 
most range of the Himalaya, and gain possession of the drainage of the 
plateaus beyond ; for then, as the high-level waters find a steep outlet to a 
low-level discharge, they will carve out canons the like of which even Dutton 
has not seen, and the heavy wash of waste will shut in lakes in lateral ravines 
at many points along the lower valleys. 

In its old age, a river settles down to a quiet, easy, steady-going existence. 
It has overcome the difficulties of its youth, it has corrected the defects that 
arose from a period of too rapid growth, it has adjusted the contentions along 
the boundary -lines of its several members, and has established peaceful rela- 
tions with its neighbors : its lakes disappear, and it flows along channels that 
meet no ascending slope on their way to the sea. 

Certain accidents to which rivers are subject are responsible for many 
lakes. Accidents of the hot kind, as they may be called for elementary dis- 
tinction, are seen in lava-flows, which build great dams across valleys : the 
marshes around the edge of the Snake river lava-sheets seem to be lakes of 
this sort, verging on extinction : crater lakes are associated with other forms 
of eruption. Accidents of the cold kind are the glacial invasions : we are 
perhaps disposed to overrate the general importance of these in the long his- 
tory of the world, because the last one was so recent, and has left its numerous 
traces so near the centers of our civilization ; but the temporary importance of 
the last glacial accident in explaining our home geography and our human 
history can hardly be exaggerated. During the presence of the ice, especially 
diiring its retreat, short-lived lakes were common about its margin. We owe 
many prairies to such lakes. The rivers running from the ice-front, overloaded 
Avith sand and silt, filled up their valleys and ponded back their non-glacial 
side-streams ; their shore-lines have been briefly described in Ohio and Wis- 
consin, but the lakes themselves were drained when their flood-plain barriers 
Avere terraced ; they form an extinct species, closely allied to the existing 
Danube and Eed Eiver type. As the ice-sheet melts away, it discloses a sur- 
face on Avhich the drift has been so irregularly accumulated that the new 
drainage is everywhere embarrassed, and lakes are for a time very numerous. 
Moreover, the erosion accomplished by the ice, especially near the centers of 
glaciation, must be held responsible for many, though by no means for most, 
of these lakes. Canada is the American type, and Finland the European, of 
land-surface in this condition. The drainage is seen to be very immature, but 
the immaturity is not at all of the kind that eliaracterized the first settlement 
of rivers on these old lands : it is a case, not of rejuvenation, but of regenera- 
tion ; the icy baptism of the lands has converted their streams to a new spirit 
of lacustrine hesitation unknown before. We cannot, however, expect the 



120 SUPPLEMENT. 

conversion to last very long : there is already apparent a backsliding to the 
earlier faith of steady flow, to which undisturbed rivers adhere closely through- 
out their lives. 

Water-surface is, for the needs of man, so unlike land-surface, that it is 
natural enough to include all water-basins under the single geographic term, 
' lakes.' Wherever they occur, — in narrow mountain-valleys or on broad, level 
plains ; on divides or on deltas ; in solid rock or in alluvium, — they are all 
given one name. But if we in imagination lengthen our life so that we wit- 
ness the growth of a river-system as we now watch the growth of plants, we 
must then as readily perceive and as little confuse the several physiographic 
kinds of lakes as we now distinguish the cotyledons, the leaves, the galls, and 
the flowers, of a quickly grooving annual that produces all these forms in 
appropriate order and position in the brief course of a single summer. 

, W. M. DAVIS. 

Cambridge, Ma,ss., September 7, 1887. 



L.iKES OF NOKTH AMERICA. 



Plate 23. 




SKETCH OF PYRAMID ISLAND, PYRAMID LAKE, NEVADA. 



X_ 



II^DEX, 



Abbott, Humphreys and, Cited on rafts in 

Eed river, La., 27. 
Abert lake, Oregon, Analysis of, 72. 

Origin of, 30. 

Agassiz, Lake, Description of, lO-j-1.06. 

• Eeference to, 2. 

Aleutian islands. Lakes on, 20. 

Algae, Precipitation of lime and iron by, 

76, 77. 
Alluvial cones. Obstruction of drainage by, 6. 
Analysis of the waters of alkaline and saline 

lakes, Table of, 72. 
Analysis of the Avaters of fresh lakes, 55-57. 

■ Qreat Salt lake, by E. Waller, 81. 

• Mono lake, by T. M. Chatard, 88. 

St. Lav?rence river, by T. S. Hunt, 60. 

Andrews, E., Cited on erosion, 60. 
Annie, Lake, Cal., Origin of, 10. 
Aqueous agencies. Lake basins due to, 5-10. 
Areas of Laurentian lakes, 58. 
Atmospheric agencies, basins due to, 3-5. 
Au Train island. Gravel spit on, 48. 

Bars, Origin of, 47, 48. 

Bear-wallows, 28. 

Beaver dams, Lakes formed by, 27. 

Belleville, Out., Height of ancient beach 

at, 100. 
Bischof, G., Cited on chemistry of water, 55. 
BoLsena, Lago di, Ital., ]\Iention of, 20. 
Bonney, T. G., Cited on rock-basins, 41. 
Bonneville, Lake, Deltas in, 50. 

Description of, 106-109. 

Lakes in basin of, 29. 

Overflow of, 39. 

Borgne, Lake, La., r)rigin of, 8. 
Bracciano, Lago di, Ital., Mention of, 20. 
Brienz, Lake, Switz., Eeference to, 7. 
Brigliam, A. P., Cited on Finger lakes, 

N. Y., 16. 
Buffalo, X. Y., Else of wati^r at. 30. 
Buffalo-wallows, 28. 



Calderas or crater-rings, 20. 

Canadian river, X. ^I., Lava flow in canon 

of, 18. 
Carboniferous lakes, Brief notice of, 115. 
Cascades, Basins excavated by, d-6. 
Caspian sea, Brief account of, 69. 
Castani, Lake, Alaska, Origin of, 11. 
Catskill Mts., Eeference to, 116. 
Cayuga, Lake, N. Y., Origm of, 16. 
Cliaix hills, Alaska, Lakes near, 11, 12. 
Champlain, Lake, Terraced borders of , 92. 
Chatard, T. M., Analysis of the water of 

Mono lake by, 88. 

Cited on analysis of lake water, 72. 

Chelan City, Wash., Mention of, 66. 
Chelan, Lake, Wash., Description of, 05-69. 
Chemical action. Basins due to, 31, 32. 
Chemistry of lake waters, 55-00, 69-77, 

81-88. 
Chicago, 111., Else of water at, 34. 
Cinder Cone, Cal., Lakes near, 18. 
Cleveland, 0., Erosion near, 61. 
Climate, Influence of, on lakes, 37, 38. 
Climatic conditions, E elation of, to lakes, 54. 
Coast Survey, U. S., Charts of, 9. 
Cochituate, Lake, Mass., Origin of, 17. 
Color, Prevailing, of lake beds, 41. 
Colimibia river. Wash. , Lakes in old channel 

of, 5, 6. 
Commerce of the Laurentian lakes, 01, 62. 
Como, Lake, Ital., Mention of, 15, 64. 
Comstock, C. B., Cited on Lake Survey, 57. 
Coon butte, Ariz., Description of, 21, 22. 
Crater lake. Ore., Description of, 20, 21. 

Mention of, 64. 

Crater lakes. Origin of, 19. 
Cro.sman, C, Eecords of erosion, In', 60. 
Croton river, N. Y., Soluble matter in, 56. 
Currents, Waves and, in lakes, 33, 34. 

Dana, E. S., Cited on thinolitic tufa, 112. 
Dana, Mt., Cal., View from, 84, 85. 



122 



INDEX, 



Davis, W. M., Cited on classification of 
lalces, 1, 117-120. 

Cited on crater lakes, 19. 

Cited on lakes of Red river, 8. 

Cited on lakes retained by deltas, 7. 

Dav^^son, J. W., Cited on carboniferous fos- 
sils, 115. 

Cited on Pleistocene history of Lauren- 

tian basin, 102. 

Dawson, W. M., Cited on Lake Yukon, 17. 

Delta in Lake St. Clair, Origin of, 40. 

Deltas, Formation and structure of, 48-51. 

Deltas, Lakes on, 8. 

Dendritic tufa. Origin of, 110. 

Detroit river, Area, water-shed, etc., of, 58. 

Diasti'ophism, Lakes due to, 28-31. 

Diatomaceous earth, Origin of, 42. 

Dieulafait, M., Cited on precipitation of 
salts, 74. 

Diller, J. S., Cited on lakes in Cal., 18. 

Dirt glacier, Alaska, Lake retained by, 11. 

Drummond lake, Va. , Origin of, 26. 

Dunes retaining lakes, 4. 

Dutton, C. E., Cited on Crater lake, Ore., 20. 

Earthquakes, Basins due to, 25, 26. 
Erie, Lake, Currents in, 34. 

Effects of gale on,- 84. 

Erosion of the shores of, 61. 

Embankments, Origin of, 46-48. 
Erosion of lake shores, 60. 

Fault-basins, Description of, 29, 30. 

Reference to, 2. 

Finger lakes, N. Y., Origin of, 16. 
Fisheries of the Laurentian lakes, 62. 
Florida, Lakes on new land in, 1. 
Flow of streams, Influence of lakes on, 38, 39. 
Fort Bidwell, Cal., Lake Annie, near, 10. 
Fossils in sediments of lakes Bonneville and 
Lahontan, 114. 



of. 



Soda lakes. 



Gaylussite, formation 

Nev., 73, 74. 
Geneva, Lake, Switz., Delta in, 91. 

Purity of water in, 40. 

Gilbert, G. K., Cited on age of Great Salt 

lake, 82. 

Cited on Coon butte, Ariz., 21, 22, 24. 

Cited on ice-walls, 52, 53. 

Cited on Lake Bonneville, 106. 



Gilbert, G. K., Cited on lake in Ice Spring 
butte, Utah, 19. 

Cited on lunar craters, 24, 25. 

Cited on Pleistocene history of Lauren- 
tian basin, 96. 

Cited on wind-erosion basins, 3. 

Glacial agencies, Lakes due to, 10-17. 

Glaciers, Lakes on, 10, 11. 

Glen Roy, Scotland, Ancient beaches in, 12. 

Grand Coulee, Wash., Lakes in, 5. 

Great Basin, Origin of lakes in, 2. 

Pleistocene lakes of, 106-114. 

Great lakes, Pleistocene history of, 96-103. 

Great Plain of the Columbia, lakes on, 4, 5-6. 

Great Salt lake, Utah, Analysis of, 72. 

Description of, 77-83. 

Precipitation of sodium sulphate in, 75. 

See also Laurentian lakes. 

Gustavila, Lake, Mex., Mention of, 20. 

Gypsum, Basins due to solution of, 32. 

Hamilton, Ont., Height of ancient beach 
at, 100. 

Hay den, F. V. , Cited on Twin lakes. Col. , 14. 

Hayes, C. W., Cited on lakes in Alaska, 17. 

Hudson river, N. Y. , Soluble matter in, 56. 

Hull, E., Cited on Laacher See, 19. 

Humboldt lake, Nev., Analysis of, 72. 

Origin of, 10. 

Humphreys and Abbott, Cited on rafts in 
Red river. La. , 27. 

Hunt, T. S., Analysis of water of St. Law- 
rence by, 60. 

Huron, Lake, Area, depth, etc., of, 58, 59. 

Currents in, 34. 

Ice-built walls. Origin of, 51-53. 
Ice Spring butte, Utah, Lake in, 19. 
Inland Salt Co., Utah, Operations of, 82. 
Iroquois, Lake, Brief account of, 99. 

Judd, J. W., Cited on Calderas, 20. 

King, C, Cited on Lake Lahontan, 106. 

Cited on thinolite, 110. 

Klamath lake, Ore. , Mention of, 20. 
Krakatoa, Eruption of, 21. 

Laacher See, Germany, Mention of, 19. 
Lahontan, Lake, Nev., Description of, 106- 
114. 



INDEX. 



123 



Lahontan, Lakes in basin of, 10, 29. 
Lake Survey, U. S. , Cliarts of, 9, 48, 49. 

Tides observed by, 33. 

Work of, 57, 58. 

Land slides. Basin formed by, 31. 
Laurentian basin. Pleistocene history of, 96- 

103. 
Laurentian lakes. Account of, 57- 

Areas of, 58. 

Color of clays in, 41. 

Currents in, 33, 34. • 

Erosion of tlie shores of, 60. 

See also Great lakes. 

Lawson, A. C, Cited on Pleistocene history 

of Laurentian basin, 96, 100. 
Le Conte, John, Cited on Lake Tahoe, 64. 
Observations by, in Lake Tahoe, Cal. — 

Nev., 35-37. 
Life histories of lakes, 90-95. 
Lithoid tufa, Origin of, 110. 
Lockyer, N., Cited on meteoric hypothesis, 

24. 
Loess, Origin of, 11. 
Logan, L'tah, Delta near, 50. 
Louas lake, India, Description of, 23. 
Lyell, C, Cited on rafts in Red river. La., 27. 

Maggiore, Lake, Ital., Mention of, 64. 

Reference to, 15. 

Malaspina glacier. Lakes near, 9, 11. 

Manitoba, Lakes in, 7. 

Manitou island. Lake Michigan, Sea cliff on, 
42. 

]Marjelen lake, Switz., Origin of, 11. 

Mechanical sediments. Deposition of, 41. 

^IcGee, W. J., Cited on New Madrid earth- 
quake, 25. 

Meteoric hypotliesis. Reference to, 24. 

Meteors, Basins due to impact of, 24, 25. 

Michigan, Lake, Area, depth, etc., of, 58, 59. 

Currents in, 34. 

Effects of gale on, 34. 

Erosion of the shores of, 60, 61. 

Iniiuence of, on climate, 38. 

Mississippi delta, '' Mud lumps" on, 28. 

Missi.ssippi river. Soluble matter in, 56. 

Mono lake, Cal., Analysis of, 72, 88. 

Ci-ater-lake in, 19. 

Description of, 83-89. 

Lake on island in, 24. 

Moraine lake^ near, 14. 



Mono Lake, Cal., Recent fault near, 30. 

Tufa bowl near, 32. 

Moon, Origin of craters on, 24. 
Mora river, N. M., Lava flow in canon of, 18. 
Moses lake, Wash. , Origin of, 4. 
Mountain lakes. Examples of, 63-69. 
Muir, J., Cited on lake in Stikiue valley, 
Alaska, 11. 

New land areas, lakes on, 1-3. 

New Madrid earthquake. Lakes formed by, 

25. 
Niagara river. Area, water-shed, etc. , of, 58. 
Newberry, J. S., Cited on lakes in coal 

swamps, 115. 

Oldham, R. D., Cited on Lonas lake, Ind., 23. 
Ontario, Lake, Area, depth, etc., of, 58, 59. 

Currents in, 34. 

Oolitic sand. Origin of, 77. 
Organic agencies. Basins due to, 26-28. 
Owens lake, Cal., Analysis of, 72. 
Ox-bow lakes, Origin of, 8. 

Parks of Colorado, Origin of, 15. 
Peat bogs. Drainage of, 42. 
Pepin, Lake, Origin of, 7. 
Perkins, E. A., Cited on Seiches, 35. 
Playa lakes. Origin of, 70, 71. 
Pleistocene lake-beds. Color of, 41. 
Poe, 0. M. , Lake surveys by, 58. 
Pontchartrain, Lake, La., Origin of, 8. 
Powell, J. W., Cited on obstructions in Colo- 
rado river, 7. 
Precipitates from saline lakes, 71-77. 
Pyramid lake, Xev., Analysis of, 72. 

Rain-fall in Laurentian basin, 59. 
Ragtown, Nev., Salts formed in lakes near, 
73. 

See also Soda lakes. 

Ramsay, A. C, Cited on rock-basms, 15. 
Red river. La., Lakes on, 8. 

Timber rafts in, 27. 

Rhone, Delta of, 91. 

Rock-basins made by glaciers, 13, 14. 

Rock-basins, Origin of, 4. 

Roth, J., Cited on chemistry of water, 55. 

Rothplitz, A., Cited on oolitic sand, 77. 

Rusli, Lake, Utah, Origin of, 9, 10. 

Russell, Thomas, Cited on evaporation, 59. 



124 



INDEX. 



St. Clair, Lake, Area, water-shed, etc., of, 

58. 

Delta formed in, 40. 

St. Clair river. Area, water-slied, etc., of, 

58. 
St. Lawrence basin, Eain fall in, 59. 
St. Lawrence river. Analysis of, 60. 

Volume of, 58. 

St. Mary's river. Area, water-shed, etc., of, 

58. 
St. Mary's river. Else of water in, 34, 39. 
Saline lakes, Description of, 69-89. 
Sault de St. Marie, see also Saint Mary's 

river. 

Vessels passing, 61. 

Sandusky, O., Lakelets near, 28. 
Sea cliffs. Origin of, 43-45. 
Sediments in lakes, 39, 40. 
Seneca lake, N. Y. , Deltas in, 49, 50. 
Seiches, Brief account of, 35. 
Sevier lake, Utah, Analysis of, 72. 
Sink-holes, Ponds formed in, 31. 
Smoke creek desert, Nev., Lakes on, 27, 28. 
Schermerhorn, L. Y., Cited on physical feat- 
ures of Laurentian lakes, 58. 
Soda lake, Nev., Analysis of, 72. 

Origin of, 19. 

See also Kagtown ponds. 

Soap lake. Wash., Analysis of, 72. 

Spencer, J. W., Cited on Pleistocene history 

of Laurentian basin, 96, 102. 
Stevenson, J. J. , Cited on lava flow in New 

Mexico, 18. 

Cited on Twin lakes, Col. , 14. 

Stikine river, Alaska, Glacial lake in valley 

of, 11. 
Stockton, Utah, Small lake near, 9, 10. 
Stockton bar, Utah, Brief account of, 10. 

Map of, 12. 

Suez Canal, Commerce of, 61. 

Superior, Lake, Ancient beaches on shores 

of, 101. 

Area of, 57. 

Area, depth, etc., of, 58, 59. 

Color of clays in, 41. 

■ Currents in, 34. 

• Precipitous shores of, 45. 

Rise of water in, 39. 

Sand bars on shore of, 48. 

Swallow-holes, Ponds formed in, 31. 
Sweden, Lake ores of, 77. 



Symons, T. W., Cited on the Upper Colum- 
bia, 68. 
Syracuse, N. Y., Salts from brines of, 73. 

Tahoe, Lake, Cal.— Nev., Depth of, 21. 

Description of, 63-65. 

-Mention of, 67, 68. 

Temperature of, 35-37. 

Tarr, R. S., Cited on Lake Cayuga, 16. 

Taylor, F. B., Cited on delta in St. Clair 
lake, 40. 

Cited on Pleistocene history of Lauren- 
tian basin, 96-101. 

Temperature of deep lakes, 35, 36. 

Lake Tahoe, 64. 

Terraces, Origin of, 44-46. 

Tertiary lakes. Brief notice of, 115. 

Thinolite, Nature of, 110. 

Thinolitic tufa. Origin of, 110-113. 

Thun, Lake, Switz., Reference to, 7. 

Tides in Laurentian lakes, 33. 

Toledo, 0. , Rise of water at, 34. 

Toronto, Can., Height of ancient beach at, 
100. 

Topography of lake shores, 43-49. 

Toulca, Mt. , Mex. , Lake in, 19. 

Toyatte glacier, Alaska, Lake retained by, 
11. 

Truckee river. Obstructed by sand, 4. 

Tufa in Lahontan basin, 110-114. 

Tulare, Lake, Cal., Origin of, 6. 

Tundras, Origin of lakes on, 26. 

Twin lakes. Col., Origin of, 14. 

Tyrroll, J. B., Cited on ice-walls, 52. 

U. S. Fish Commission, Cited on fisheries of 

Laurentian lakes, 6. 
Upham, Warren, Cited on Lake Agassiz, 7, 

104. 
Cited on lakes Walden and Cochituate, 

17. 

Victoria Nyanza, Lake, Area of, 57. 
Volcanic agencies. Lakes due to, 17-24. 
Volcanic dust. Obstruction of drainage by, 4. 

AVakatipu, Lake, N. Z., Origin of, 15. 
Walden, Lake, Mass., Origin of, 17. 
Walker lake, Nev., Analysis of, 72. 
Waller, E., Analysis of water of Great Salt 
lake by, 81. 



INDEX. 



125 



"Warren, G. K., Cited on Lake Pepin, 7. 

Cited on outlet of Lake Agassiz, 104. 

Warren, River, Source of, 104. 
Watkins, X. Y., Deltas near, 49, 50. 
Watertown, X. Y., Height of ancient beach 

at, 100. 
Waves and currents of lakes, 33-39. 
Weather Bureau, U. S. , Currents in Lauren- 

tian lakes observed by, 33, 34. 
Weed, W. II., Cited on deposits of hot 

springs, 77. 
White, A. C, Cited on ice-walls, 52. 



Wind-erosion basins. Origin of, 3. 
Winchell, A., Cited on isothermals of the 

Lake Region, 38. 
Winnemucca lake, Nev., Analysis of, 72. 
Winnipegasie, Lake, Ice-walls of, -52. 

Yellowstone park. Precipitates from waters 

in, 70, 77. 
Yukon, Lake, Alaska, Origin of, 17, 18. 
Yukon river, Alaska, Drift timber in, 27. 

Zuyder Zee, Origin of, 8. 



% 



